Alpha2 Capricorni

Alpha2 Capricorni (α2 Capricorni), or Algedi , is a triple star system in the southern constellation of Capricornus. It is visible to the naked eye with an apparent visual magnitude of +3.57. It is separated from the fainter α¹ Capricorni by 0.11° of the sky, a gap just resolvable with the naked eye, similar to Mizar and Alcor. Based on parallax shift as refined from orbits around the sun of the Gaia spacecraft at earth's Lagrange point 2, the star is 101 to 103 light years from the solar system.
Properties.
The primary, component A, is an evolved G-type star with a stellar classification of G8.5III-IV, indicating that the spectrum displays mixed traits of a giant and subgiant star. At the age of 1.3 billion years, is currently on the red giant branch and is generating energy through hydrogen fusion along a shell surrounding an inert helium core. The star has around double the mass of the Sun and has expanded to more than eight times the Sun's radius. The star is radiating 40 times the solar luminosity from its photosphere at an effective temperature of 5,030 K.
The secondary components B and C form a binary system that orbit each other with a period of about 244 years. Both stars have masses about half that of the Sun. They orbit the primary with an estimated period of around 1,500 years. As of 2010, the pair lies at an angular separation of 6.6 arc seconds from the primary along a position angle of 196°.
Nomenclature.
"α² Capricorni" (Latinised to "Alpha² Capricorni") is the star's Bayer designation. It bore the traditional names "Secunda Giedi" or "Algiedi Secunda" and shared the name "Algedi" (from the Arabic "الجدي" "al-jadii" 'the goat') with α¹ Capricorni. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name "Algedi" for "α² Capricorni" on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.
In Chinese, (), meaning "Ox (asterism)", refers to an asterism consisting of α² Capricorni, Beta Capricorni, ξ² Capricorni, Pi Capricorni, Omicron Capricorni and Rho Capricorni. Consequently, α² Capricorni itself is known as (, .)


V763 Centauri

C1 Centauri is a single star in the southern constellation of Centaurus. It has the variable star designation V763 Centauri, while "C1 Centauri" is the Bayer designation. The star has a red hue and is dimly visibly to the naked eye with an apparent visual magnitude that fluctuates around +5.64. It is located at a distance of approximately 600 light years based on parallax, and has an absolute magnitude of −1.05. It is drifting further away with a radial velocity of +21 km/s. At one time it was a candidate member of the Zeta Herculis Moving Group but has since been excluded.
This object is an aging red giant star on the asymptotic giant branch with a stellar classification of M3/4III. Samus et al. (2017) classify this as a slow irregular variable of sub-type Lb and its brightness varies from magnitude +5.52 down to +5.82. It was previously classified as a semiregular variable of sub-type SRb. With the supply of hydrogen and helium at its core exhausted, the star has expanded until now it has 65 times the radius of the Sun. It is radiating 754 times the luminosity of the Sun from its photosphere at an effective temperature of 3,761 K.


HD 89998

HD 89998 (r Velorum) is a single star in the southern constellation of Vela. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.82. The distance to HD 89998, as determined from its annual parallax shift of , is 205 light years. The star is moving further from the Earth with a heliocentric radial velocity of +21 km/s, having come within some 1.552 million years ago.
This is an evolved giant star with a stellar classification of K1 III. The measured angular diameter of this star, after correcting for limb darkening, is . At the estimated distance of this star, this yields a physical size of 11.6 times the radius of the Sun. It is radiating 54 times the Sun's luminosity from its enlarged photosphere at en effective temperature of 4,812 K.
References.
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Denebola

Denebola , designated Beta Leonis (β Leonis, abbreviated Beta Leo, β Leo) is the second-brightest star in the zodiac constellation of Leo, although the two components of the γ Leonis double star, which are unresolved to the naked eye, have a combined magnitude brighter than it. Denebola is an A-type main sequence star with 75% more mass than the Sun and 15 times the Sun's luminosity. Based on parallax measurements from the Hipparcos astrometry satellite, the star is at a distance of about from the Sun. Its apparent visual magnitude is 2.14, making it readily visible to the naked eye. Denebola is a suspected Delta Scuti type variable star, meaning its luminosity varies very slightly over a period of a few hours.
Nomenclature.
"β Leonis" (Latinised to "Beta Leonis") is the star's Bayer designation. In Johann Bayer's "Uranometria" (1603), it was designated β (Beta) as the second-brightest star in the constellation. It also bears the Flamsteed designation of "94 Leonis" (assigned on the basis of increasing right ascension rather than luminosity) and additional designations followed as the star was recorded in subsequent star catalogues.
The traditional name "Denebola" is shortened from ', from the Arabic phrase ' "" 'tail of the lion', as it represents the lion's tail, the star's position in the Leo constellation. (Deneb in Cygnus has a similar name origin.) In the "Alphonsine Tables" it was recorded as Denebalezeth. On R. A. Proctor's 1871 star chart of the Northern Hemisphere it was designated "Deneb Aleet". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN, which included "Denebola" for this star. It is now so entered in the IAU Catalog of Star Names.
15th century astronomer Ulugh Beg, gives the name "Al Ṣarfah", the Changer (i.e. of the weather), as the star's individual title. Al-Biruni, a Muslim scholar and polymath of the 11th century, wrote of it: "The heat turns away when it rises, and the cold turns away when it disappears."
Ancient Chinese astronomers designated it the first star of the five-star asterism "Seat of the Five Emperors", hence its Chinese name 五帝座一 ("Wǔdìzuò-yī").
In Hindu astronomy, Denebola corresponds to the Nakshatra (a sector along the ecliptic) named "Uttara Phalgunī" (second reddish one).
Denebola, along with Spica and Arcturus, is part of the Spring Triangle asterism, and by extension, also of the Great Diamond together with the star Cor Caroli.
Properties.
Denebola is a relatively young star with an age estimated at less than 400 million years. Interferometric observations give a radius that is about 173% that of the Sun. However, the high rate of rotation results in an oblate shape with an equatorial bulge. It has 75% more mass than the Sun, which results in a much higher overall luminosity and a shorter life span on the main sequence.
Based upon the star's spectrum, it has a stellar classification of A3 Va, with the luminosity class 'Va' indicating this is a particularly luminous dwarf, a main sequence star that is generating energy through the nuclear fusion of hydrogen at its core. The effective temperature of Denebola's outer envelope is about 8,500 K, which results in the white hue typical of A-type stars. Denebola has a high projected rotational velocity of 128 km/s, which is of the same order of magnitude as for the very rapidly rotating star Achernar. The Sun, in comparison, has an equatorial rotation velocity of 2 km/s. This star is believed to be a Delta Scuti variable star that exhibits fluctuations in luminosity of 0.025 magnitudes roughly ten times per day.
Denebola shows a strong infrared excess, showing a circumstellar debris disk of cool dust in orbit around it. The dust surrounding Denebola has a temperature of about . Observations with the Herschel Space Observatory have provided resolved images, which show the disk to be located at a radius of 39 astronomical units from the star, or 39 times the distance from the Earth to the Sun. As the solar system is believed to have formed out of such a disk, Denebola and similar stars such as Vega and Beta Pictoris may be candidate locations for extrasolar planets.
Kinematic studies have shown that Denebola is part of a stellar association dubbed the IC 2391 supercluster. All the stars of this group share a roughly common motion through space, although they are not gravitationally bound. This suggests that they were born in the same location, and perhaps initially formed an open cluster. Other stars in this association include Alpha Pictoris, Beta Canis Minoris and the open cluster IC 2391. In total more than sixty probable members of the group have been identified.
In culture.
In astrology, Denebola was believed to portend misfortune and disgrace.


Upsilon Pegasi

Upsilon Pegasi, Latinised from υ Pegasi, is a star within the great square in the northern constellation of Pegasus. It has the proper name Alkarab . This object has a yellow-white hue and is faintly visible to the naked eye with an apparent magnitude of 4.40. It is located at a distance of approximately 170 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −8.6 km/s. The star is moving through the Galaxy at a speed of 50.6 km/s relative to the Sun. Its projected Galactic orbit carries it between 18,600 and 26,300 light-years from the center of the Galaxy.
This object is an aging giant star with a stellar classification of F8III. It is currently in the Hertzsprung gap and is a source of X-ray emission. The star has 2.2 times the mass of the Sun and is spinning with a projected rotational velocity of 73.4 km/s. It has an iron abundance of −0.01 dex, or 97.7% of the Sun's. Upsilon Pegasi has six times the girth of the Sun and is radiating 43 times the Sun's luminosity at an effective temperature of 6,061 K.
Nomenclature.
"υ Pegasi" is the star's Bayer designation. The star bore the traditional Arabic name "Al Karab" ("the Bucket-rope"). In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name "Alkarab" for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.


Gliese 393

Gliese 393, or GJ 393, is a single star in the equatorial constellation of Sextans, positioned about 1.5° to the NNW of Beta Sextantis. At an apparent visual magnitude of 9.65, it is much too faint to be seen with the unaided eye. This star is located at a distance of 22.9 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +8.3 km/s. It has a large proper motion, traversing the celestial sphere at the rate of per year. The net velocity of this star relative to the Sun is 32.9 km/s. It shares a similar space motion as members of the AB Doradus moving group, but is considered a random interloper.
The stellar classification of GJ 393 is M2V, indicating this is a small red dwarf star that is generating energy through core hydrogen fusion. It is rotating slowly and appears to be chromospherically inactive, suggesting it is an older star; perhaps as much as 10 billion years old. The star has 43% of the mass of the Sun and 44.6% of the Sun's radius. The metallicity, what astronomers term the abundance of heavy elements, is lower than in the Sun. It is radiating just 2.7% of the Sun's luminosity from its photosphere at an effective temperature of 3,579 K.
Planetary system.
In 2019 one candidate planet been detected by the radial velocity method. It is classified as a hot super-Earth, with an orbital period of one week and a semimajor axis of . Longer period signals found in the data were interpreted as stellar activity.


Beta Coronae Australis

Beta Coronae Australis, Latinized from β Coronae Australis, is a single star in the southern constellation of Corona Australis. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.10. The star is located around 470 light years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +3 km/s.
This is an aging K-type giant/bright giant star with a stellar classification of K0II/IIICNIb, where the suffix notation indicates an abundance anomaly of CN in the spectrum. Having exhausted the supply of hydrogen at its core, the star has expanded to 41 times the girth of the Sun. It shines with a luminosity approximately 694 times that of the Sun and has a surface temperature of 4,771 K.


NGC 6325

NGC 6325 is a globular cluster located in the constellation Ophiuchus. Its Shapley-Sawyer Concentration Class is IV, meaning that it has "intermediate rich concentration"; it was discovered by the British astronomer John Herschel on 24 May 1835. It is at a distance of about 25,000 light years away from earth.


Z Ursae Minoris

Z Ursae Minoris (Z UMi) is a carbon star and R Coronae Borealis variable in the constellation Ursa Minor.
Z Ursae Minoris was discovered to be a variable star in 1934. It was catalogued as a probable Mira variable, due to its red colour and variations over several hundred days. It was discovered to be a carbon star in a survey published in 1985, and subsequently found also to be hydrogen-deficient. After fading by almost six magnitudes in 1992, it was classified as an R Coronae Borealis variable. It was confirmed as an R Coronae Borealis variable, one of the coolest in the class, after its spectrum was analysed in 2006.


NGC 6850

NGC 6850 is a barred lenticular galaxy in the constellation Telescopium, discovered by John Herschel in 1836.


Xi Aurigae

Xi Aurigae, Latinized from ξ Aurigae, is the Bayer designation for a single, white-hued star in the northern constellation of Auriga. This star was once considered part of the constellation of Camelopardalis and held the Flamsteed designation 32 Camelopardalis. It is visible to the naked eye with an apparent visual magnitude of +5.0. The measured annual parallax shift of this star is , which corresponds to a physical distance of with a 5 light-year margin of error. At that distance, the visual magnitude of the star is diminished by an extinction of 0.108 due to interstellar dust.
This is an A-type main sequence star with a stellar classification of A2 Va. Although it was one of the first stars to be cataloged as a Lambda Boötis star, Murphy et al. (2015) don't consider it to be a member of this population. The star has nearly twice the mass of the Sun and about 1.1 times the Sun's radius. It is an estimated 174 million years old and is spinning with a projected rotational velocity of 62 km/s. Xi Aurigae is radiating 49.5 times the Sun's luminosity from its photosphere at an effective temperature of around 9,152 K.


NGC 7252

NGC 7252 is a peculiar galaxy resulting from an interaction between two galaxies that started a billion years ago. It is located 220 million light years away in the constellation Aquarius. It is also called Atoms for Peace Galaxy, a nickname which comes from its loop-like structure, made of stars, that resembles a diagram of an electron orbiting an atomic nucleus.
Description.
NGC 7252 is located in the southern part of Aquarius. With an apparent magnitude of 12.7, it is bright enough to be seen by amateur astronomers as a faint small fuzzy blob. Large loops of gas and stars around it makes the galaxy quite peculiar. Thus, it is also Arp 226 (the 226th entry in Arp's list of peculiar galaxies).
In December 1953, U.S. President Dwight D. Eisenhower gave the "Atoms for Peace" speech. The speech was concerned about promoting nuclear power for peaceful purposes instead of nuclear weapons. Significant to the scientific community, the name of the speech was given to this peculiar galaxy. The two galaxies merging also resembles nuclear fusion and the galaxies giant loops resemble a diagram of electrons orbiting the nucleus of an atom.
The galaxy is the result of a collision of two galaxies. This collision is an opportunity for astronomers to study such mergers and to predict the future of our Milky Way after its expected collision with the Andromeda Galaxy.
X-ray emissions were observed in NGC 7252. This suggests the existence of nuclear activity or an intermediate-mass black hole in the galaxy.
Structure.
The central region of the galaxy is home to hundreds of massive, ultra-luminous clusters of young stars that appear as bluish knots of light. These young clusters were created on the suspected galaxy merger, that pushed gases into these regions and caused a burst of star formation.
The most conspicuous of them is one known as W3, which has a mass of around 8*107 solar masses. This object, also the most luminous super star cluster known to date, has properties more similar to an ultra-compact dwarf galaxy and differs only from those galaxies because of its age (300–500 million years).
A pinwheel-shaped disk, rotating in a direction opposite to that of the galaxy, is found deep inside NGC 7252: it resembles a face-on spiral galaxy, yet it is only 10,000 light years across. It is believed that this pinwheel-shaped structure is a remnant of a collision between two galaxies. Within a few billion years, NGC 7252 will look like an elliptical galaxy with a small inner disk due to the exhaustion of the gases in the galaxy.
In August 2013, F. Schweizer and others published a paper in the "Astrophysical Journal" titled "The [O III] Nebula of the Merger Remnant NGC 7252: A Likely Faint Ionization Echo". This reports the finding of a Voorwerpje on the outskirts of the well-studied NGC 7252. The abstract states (edited): "We present images and spectra of a ~10 kpc-sized emission-line nebulosity discovered in the prototypical merger remnant NGC 7252 and dubbed the `[O III] nebula' because of its dominant [O III]_5007 line. This nebula seems to yield the first sign of episodic AGN activity still occurring in the remnant, ~220 Myr after the coalescence of two gas-rich galaxies. Its location and kinematics suggest it belongs to a stream of tidal-tail gas falling back into the remnant." It continues: "This large discrepancy suggests that the nebula is a faint ionization echo excited by a mildly active nucleus that has declined by ~3 orders of magnitude over the past 20,000–200,000 years. In many ways this nebula resembles the prototypical `Hanny's Voorwerp' near IC 2497, but its size is 3x smaller."


Kepler-80

Kepler-80, also known as KOI-500, is a red dwarf star of the spectral type M0V. This stellar classification places Kepler-80 among the very common, cool, class M stars that are still within their main evolutionary stage, known as the main sequence. Kepler-80, like other red dwarf stars, is smaller than the Sun, and it has both radius, mass, temperatures, and luminosity lower than that of our own star. Kepler-80 is found approximately 1,218 light years from the Solar System, in the stellar constellation Cygnus, also known as the Swan.
The Kepler-80 system has 6 known exoplanets. The discovery of the five inner planets was announced in October 2012, marking Kepler-80 as the first star identified with five orbiting planets. In 2017, an additional planet, Kepler-80g, was discovered by use of artificial Intelligence and deep Learning to analyse data from the Kepler space telescope. The method used to discover Kepler-80g had been developed by Google, and during the same study another planet was found, Kepler-90i, which brought the total number of known planets in Kepler-90 up to 8 planets.
Planetary system.
The exoplanets around Kepler-80 were discovered and observed using the Kepler Space Telescope. This telescope uses the so called "transit method", where the planets move in between the star and the Earth and thereby dim the light of the star as seen from the Earth. By using photometry the transit of a planet in front of its star can be seen as a dip in the light curve of the star. After the initial discovery the five innermost planets have all been confirmed through additional investigations. Kepler-80b and Kepler-80c were both confirmed in 2013 based on their transit-timing variation (TTV). Kepler-80d and Kepler-80e were validated in 2014 based on statistical analysis of the Kepler data. Finally the innermost planet, Kepler-80f was confirmed in 2016.
All six known planets in the Kepler-80 system orbit very close to the star, and their distances to the star (the semi-major axes are all smaller than 0.2 AU). For comparison the planet in the Solar System closest to the star, Mercury, has a semi major axis of 0.389 AU, and so the entire known system of Kepler-80 can lie within the orbit of Mercury. This makes Kepler-80 a very compact system and it is one of many STIP's (Systems with Tightly-packed Inner Planets) that have been discovered by the Kepler telescope.
In 2014, the dynamical simulation shown what the Kepler-80 planetary system have likely to undergone a substantial inward migration in the past, producing an observed pattern of lower-mass planets on tightest orbits.
Orbital resonance.
Kepler-80 d, e, b, c and g have orbits locked in a resonance. While their periods are in a ~ 1.000: 1.512: 2.296: 3.100: 4.767 ratio, in a frame of reference that rotates with the conjunctions this reduces to a ratio of 4:6:9:12:18. Conjunctions of d and e, e and b, b and c, and c and g occur at relative intervals of 2:3:6:6 in a pattern that repeats about every 191 days. Librations of possible three-body resonances have amplitudes of only about 3 degrees, and modeling indicates the resonant system is stable to perturbations. Triple conjunctions do not occur.


Lambda Sagittarii

Lambda Sagittarii (Latinized from λ Sagittarii), formally named Kaus Borealis , is a star in the southern constellation of Sagittarius. The star marks the top of the Archer's bow.
Properties.
With an apparent visual magnitude of +2.82, this is one of the brighter members of the constellation and, according to the Bortle Dark-Sky Scale, it is readily visible to the naked eye. Based upon parallax measurements, it is from the Sun.
Being 2.1 degrees south of the ecliptic, Lambda Sgr is sometimes occulted by the Moon and, rarely, by a planet. The last planet to pass in front of it was Venus, on 19 November 1984. The previous occasion was 5 December 1865, when it was occulted by Mercury.
Kaus Borealis is a subgiant star with a stellar classification of K0 IV. It has a mass 2.6 times that of the Sun and a physical size of about 11.2 times the Sun's radius. This expanded outer envelope is radiating energy at an effective temperature of 4,770 K, causing it to glow with the cool orange hue of a K-type star. It appears to be rotating at a leisurely rate, with a projected rotational velocity of .
Nomenclature.
"λ Sagittarii" (Latinised to "Lambda Sagittarii") is the star's Bayer designation.
It bore the traditional name "Kaus Borealis", which derives from the Arabic قوس "qaws" 'bow' and Latin "boreālis" 'northern'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Kaus Borealis" for this star.
This star, with Gamma Sagittarii, Delta Sagittarii, Epsilon Sagittarii, Zeta Sagittarii, Sigma Sagittarii, Tau Sagittarii and Phi Sagittarii comprises the "Teapot" asterism.
In the catalogue of stars in the "Calendarium" of Al Achsasi al Mouakket, this star was designated "Rai al Naaim", which was translated into Latin as "Pastor Struthionum", meaning "keeper of the ostriches".
This star is Al Tizini's "Rāʽi al Naʽāïm" (ألراع ٱلنعم), the Keeper of the Naʽams (Ostrich), meaning the "keeper" the two asterisms "al-Naʽām al-Wārid" ( النعام الوارد ), "The Going Ostriches" and "al-Naʽām al-Ṣādir" (النعم الصادر), "The Returning Ostriches".
In Chinese, (), meaning "Dipper", refers to an asterism consisting of Lambda Sagittarii, Phi Sagittarii, Mu Sagittarii, Sigma Sagittarii, Tau Sagittarii and Zeta Sagittarii. Consequently, Lambda Sagittarii itself is (, .)


List of stars in Centaurus

This is the list of notable stars in the constellation Centaurus, sorted by decreasing brightness.


NGC 200

NGC 200 is a spiral galaxy located in the constellation Pisces. It was discovered on December 25, 1790 by William Herschel.


Zeta Lupi

ζ Lupi (Latinised as Zeta Lupi) is the brighter component of a wide double star in the constellation Lupus, consisting of an orange-hued primary and a fainter secondary with a golden-yellow hue. It is visible to the naked eye with a combined apparent visual magnitude of 3.41. Based upon an annual parallax shift of 27.80 mas as seen from Earth, it is located 117.3 light years from the Sun.
This is a probable binary star system. As of 2013, the pair had an angular separation of 71.20 arc seconds along a position angle of 249°. The primary, component A, is an evolved G-type giant star with a visual magnitude of 3.50 and a stellar classification of G7 III. This is a red clump star, indicating that it is generating energy through the thermonuclear fusion of helium in its core region. Its measured angular diameter is , which, at the estimated distance of Zeta Lupi, yields a physical size of about 10 times the radius of the Sun.
The secondary, component B, has a visual magnitude of 6.74.
References.
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Nu Puppis

Nu Puppis (ν Puppis) is a solitary, blue-hued star in the southern constellation of Puppis. It is the fifth-brightest star in Puppis, with an apparent visual magnitude of 3.17. Based upon an annual parallax shift of 8.78 mas as seen from Earth, it is located about 370 light years from the Sun. The system made its closest approach about 3.6 million years ago when it underwent perihelion passage at a distance of roughly 27 light years.
The star has a stellar classification of B8 III, matching a B-type giant. Absorption lines in the spectrum are displaying central quasi-emission peaks, indicating this is a Be shell star with a circumstellar disk of heated gas that is being seen edge-on. ν Puppis is a candidate variable star showing an amplitude of 0.0117 magnitude with a frequency of 0.15292 per day. It is spinning rapidly with a projected rotational velocity of 225 km/s. This rotation is giving the star an oblate shape, with the equator being 31% larger than the poles. It is radiating (after allowance for ultraviolet radiation) 1,340 times the Sun's luminosity from its photosphere at an effective temperature of 12,120 K.


Uttara Ashadha

Uttara Ashadha (lit. "latter victory", "latter unconquered") is the twenty-first of the 27 Nakshatra (constellations) in Hindu astrology. It is situated on the lower part of Lyra and spans from 26°40" in Sagittarius to 10°00" in Capricorn in the sidereal Vedic zodiac.
It has 4 quarters (padas), the first one falls in Sagittarius and the last three padas fall in Capricorn. The sun (Surya) is the lord of Uttara Ashadha. It has a shape of a stage. This nakshatra is symbolised by a tusk of an elephant or by a small bed.
The individuals born in this nakshatra are believed to be one of the most attractive, well-mannered and known for their absolute calmness towards greatest aggression. Due to their sense of independence they are loners and sometimes face difficulties in marriage, the loneliness is also depicted by the animal of this star which is mongoose with no female counterpart. They are believed to be refined, soft-spoken, pure hearted, innocent, and in many cases happen to occupy a very high position in the societies.
It is believed that the person with this star rising on ascendant has remarkable personality. It is the birth star of famous personalities like George Washington, Abraham Lincoln, Indira Gandhi, Brad Pitt and Muhammad Ali.
People born under this nakshatra are given names that start with Bhe, Bho, Ja, or Ji.


58 Aquilae

58 Aquilae is a single star located around 520 light years from the Sun in the equatorial constellation of Aquila, near Eta Aquilae. "58 Aquilae" is its Flamsteed designation. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.60. This object is moving closer to the Earth with a heliocentric radial velocity of −53 km/s, and may come as close as in around 1.8 million years.
This object has a stellar classification of B9 IV, matching a late B-type subgiant star. It has 5.6 times the radius of the Sun with a high rate of spin, showing a projected rotational velocity of 110 km/s. The star is radiating 117 times the luminosity of the Sun from its photosphere at an effective temperature of 7,946 K.


NGC 3642

NGC 3642 is a spiral galaxy in constellation Ursa Major. The galaxy has a low-ionization nuclear emission-line region. It is located at a distance of circa 30 million light years from Earth, which, given its apparent dimensions, means that NGC 3642 is about 50,000 light years across. The galaxy is characterised by an outer pseudoring, which was probably formed after the accretion of gas rich dwarf galaxy.
Structure.
NGC 3642 is a spiral galaxy without bar. In the nucleus there is a supermassive black hole with estimated mass 26-31 millions M⊙, based on the intrinsic velocity dispersion as measured by the Hubble Space Telescope, or 15 millions M⊙, based on the bulge luminosities in near-infrared Ks-band.
Around the nucleus, a one-armed spiral forms a ring, and it is possible that it leads material towards the nucleus. The nucleus surrounded by an inner flocculent spiral. The outer part of the spiral forms a pseudoring that extents for about half a circle. The outer part of the spiral is warped, while its main part features an ordinary differentially rotating disk. The HI gas is also warped and extents more in the western side.
Nearby galaxies.
The galaxy belongs in NGC 3642 group (also known as NGC 3610 group), a galaxy group that also includes NGC 3610, NGC 3619, NGC 3669, NGC 3674 and NGC 3683. Other nearby galaxies include NGC 3440, NGC 3445, NGC 3458, NGC 3543 and NGC 3613.


Zeta Sagittae

Zeta Sagittae (ζ Sagittae) is triple star system in the northern constellation of Sagitta. It is visible to the naked eye, having a combined apparent visual magnitude of +5.00. Based upon an annual parallax shift of , the distance to this star is approximately .
The inner pair is a visual binary system consisting of two A-type main-sequence stars with an orbital period of , a semimajor axis of 0.136 arc seconds, and an eccentricity of 0.79. The primary, component A, has a visual magnitude of 5.64 with a stellar classification of A3 Vnn, where the 'nn' suffix indicates "nebulous" lines due to rotation. It is spinning rapidly with a projected rotational velocity of . This is giving the star an oblate shape with an equatorial bulge that is 14% larger than the polar radius.
The secondary member, component B, is a magnitude 6.04 star, while the more distant component C is magnitude 9.01 and lies at an angular separation of from the other two.
Naming.
In Chinese, (), meaning "Left Flag", refers to an asterism consisting of ζ Sagittae, α Sagittae, β Sagittae, δ Sagittae, γ Sagittae, 13 Sagittae, 11 Sagittae, 14 Sagittae and ρ Aquilae. Consequently, the Chinese name for ζ Sagittae itself is (, .)


Y Lyncis

Y Lyncis is a semiregular variable star in the constellation Lynx. It is an asymptotic giant branch star of spectral type M6S, with a luminosity class of Ib, indicating a supergiant luminosity. It is around 800 light years away.
Y Lyncis ranges in brightness from magnitude 6.8 to 8.9. Its changes in brightness are complex with at least two different periods showing. The General Catalogue of Variable Stars lists a period of 110 days. More recent studies show a primary pulsation period of 133 days, with and a long secondary period with an amplitude of 0.2 magnitudes and duration 1,300 days. The long secondary period variations are possibly caused by long-lived convection cells.
Y Lyncis has a mass around and a luminosity around . It is a thermally pulsing asymptotic giant branch star, an evolved star with a carbon-oxygen core that is fusing helium in a shell and hydrogen in a separate shell. It is also an S-type star, where third dredge-ups have brought some carbon to the surface, but not enough to create a carbon star.


72 Ophiuchi

72 Ophiuchi is a binary star system in the equatorial constellation of Ophiuchus. It is visible to the naked eye as a faint, white-hued point of light with a combined apparent visual magnitude of 3.73. It is located approximately 86.9 light years away from the Sun based on parallax, but is moving closer with a heliocentric radial velocity of -23.9 km/s.
As of 2008, the pair had an angular separation of . According to Gray et al. (2003), the primary component has a stellar classification of A5 V, matching an A-type main-sequence star. Cowley et al. (1969) had assigned it to a class of A4 IVs, suggesting it is a sharp-lined (s) subgiant star. The latter class is still in use by some sources.
The primary is 250 million years old with double the mass of the Sun and is spinning with a moderate projected rotational velocity of 65 km/s. It is radiating 20 times the luminosity of the Sun from its photosphere at an effective temperature of 8,718 K. It displays an infrared excess, suggesting a debris disk is orbiting the star with a mean separation of and temperature of 60 K. The system is a source of X-ray emission, which is most likely coming from the 14th magnitude companion.
There are additional visual companions: component C with magnitude 11.5 lies at an angular separation of from the primary, while component D, has magnitude 14.8 and separation 24".


Rho Ophiuchi

Rho Ophiuchi (ρ Ophiuchi) is a multiple star system in the constellation Ophiuchus. The central system has an apparent magnitude of 4.63. Based on the central system's parallax of 9.03 mas, it is located about 360 light-years (110 parsecs) away. The other stars in the system are slightly farther away.
System.
The central pair is known as Rho Ophiuchi AB. It consists of at least two blue-colored subgiants or main-sequence stars, designated Rho Ophiuchi A and B, respectively. Rho Ophiuchi AB is a visual binary, and the sky-projected distance between the two stars appears to be 3.1″, corresponding to a separation of at least 344 astronomical units (au). However, the actual separation is larger, and the two take about 2,400 years to complete an orbit.
Several other stars are located close to Rho Ophiuchi AB. HD 147932 is located 2.5 arcminutes away (at least 17,000 au), and is known as Rho Ophiuchi C. HD 147888 is located 2.82 arcminutes away (at least 19,000 au), and is known as Rho Ophiuchi DE. Stars C and D are both B-type main-sequence stars, and D itself is another binary with an orbital period of around 680 years.
Cloud complex.
Rho Ophiuchi is the namesake of the Rho Ophiuchi cloud complex. It is a nebula of gas and dust, which the Rho Ophiuchi system is embedded in. It is one of the easiest star forming regions to observe, as it is one of the nearest, and it is visible from both hemispheres.
The interstellar extinction (A"V") of Rho Ophiuchi is measured to be 1.45 magnitudes, meaning the dust and gas in front of Rho Ophiuchi absorbs light from the system, making it appear 1.45 magnitudes dimmer than it should be. Additionally, gas and dust also scatters more higher-frequency light, leaving the light appearing more reddish. The interstellar reddening ("EB−V") of Rho Ophiuchi has been measured to be 0.47 magnitudes.


Upsilon Capricorni

Upsilon Capricorni, Latinized from υ Capricorni, is a solitary star in the southern constellation of Capricornus. It has a reddish hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.17. The star is about 730 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −12 km/s. It is 0.22 degree north of the ecliptic, so is subject to lunar occultations.
This is an aging red giant star on the asymptotic giant branch with a stellar classification of M1 III, a star that has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has 76 times the radius of the Sun. It is a suspected variable star of unknown type with a brightness that has been measured ranging from a peak of 5.19 down to 5.24. The star is radiating 1,283 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,953 K.


HD 53705/53706/53680

HD 53705/53706/53680 is a star system that lies approximately 54 light-years away in the constellation of Puppis. The system consists of four stars in two binaries, making it one of the nearest quadruple star systems.
Component discovery.
HD 53705 was discovered to be a visual binary very early on, owing to the brightness of the two components. The earliest observation in the Washington Double Star Catalog (WDS) dates to 1826 and was made by James Dunlop, stating a position angle of 119 degrees and a separation of 21.5 arcseconds for the companion. The two stars have moved very little relative to each other since, with the most recent measurement from 1999 stating a position angle of 126 degrees and a separation of 20.9 arcseconds. This is related to the nearby location of the system: a separation of 21 arcseconds translates to a physical separation perpendicular to the line of sight of approximately 480 AU, so the orbit of the stars lasts somewhere on the order of millennia.
The companionship of HD 53680 to the closer binary was recognised later, with the first measurement in the WDS dating to 1900. With a position angle of 337 degrees and a separation of 185.7 arcseconds, HD 53680 lies on the opposite side of HD 53705 when compared to B, and is about nine times more distant. This separation results in a physical separation perpendicular to the line of sight of 4390 AU, which is atypically distant for a stellar companion but still close enough to be strongly gravitationally bound.
While all three components have similar proper motion, HD 53680's proper motion as measured by HIPPARCOS is sizeably discrepant from the proper motions of the other two components. A clue to the cause of this is that HD 53680's Tycho-2 proper motion is different from the HIPPARCOS values, which indicates that the star is being perturbed by a close companion. A fit of the HIPPARCOS astrometric data found a weakly constrained fit found a period of 1500 days, an inclination of 180 degrees (a face-on orbit) and a semimajor axis of 30.6 milliarcseconds. The fit is weakly constrained because HIPPARCOS observations do not span the full orbit of the companion, but the fit does adjust HD 53680's proper motion to be consistent with the proper motion of HD 53705/53706.
The low inclination of HD 53680 B's orbit reduces the amplitude of the radial velocity variation that it caused on HD 53680 A. In this case, the effect reduced the minimum mass of the companion into the brown dwarf regime as deduced from observations with the CORALIE spectrograph. The spectroscopic orbit produces far stronger constraint compared to the astrometry-only orbit.
Stellar properties.
HD 53705, with a spectral type of G0V, is a G-type main-sequence star that is slightly hotter, larger and brighter than our Sun. Meanwhile, HD 53706 and HD 53680 A are both K-type main-sequence stars, with spectral types of K0V and K5V, respectively. Both of these stars are substantially cooler, smaller and dimmer than the Sun.
The three stars with observed spectra in the system have similar metallicity values: [Fe/H] = -0.21 ± 0.03 and -0.28 ± 0.03 for HD 53705 and B, and [Fe/H] = -0.29 ± 0.08 for HD 53680 A. The average value, -0.26 ± 0.04, results in an iron abundance of 55 ± 5% solar, a value typical for field stars.
The sub-solar metallicity of the stars has the effect of heating up their chromospheres; Though HD 53705 has a mass that is approximately solar, its effective temperature is about fifty degrees hotter.
The kinematics of the stars, with large proper motion and radial velocity, suggests that the system is a member of the thick disk, the population of stars that comprise most of the older members of the Milky Way's spiral arms. This is supported by the parameters of HD 53705; the surface gravity of 4.34 is somewhat low for a G0V star, indicating that it is relatively old and moving towards the end of its main sequence lifetime - which, when coupled with the solar mass, mean that estimates for the star's age are approximately 9 billion years old, approximately twice the solar age. With a peculiar velocity of 75.7 km/s, The orbit of the system about the galaxy has an eccentricity of 0.31 and brings the system up to 151 parsecs away from the galactic plane - again indicative of a thick disk system.
Planet searches.
Being bright, solar-type and nearby, HD 53705 and B are attractive targets for radial velocity (RV)-based planet searches.
HD 53705 was one of the 37 targets of the first RV-based planet search in the southern hemisphere, the ESO CES survey. This survey did not detect any companion with several Jovian masses out to a few AU. An extension of this survey to the HARPS spectrograph provides further constraint, suggesting that there are no Jupiter-mass companions out to about 5 AU.
HD 53705 can be presumed to be on the CORALIE sample, as it satisfies the criteria of parallax = ≥20 mas with error ≤5 mas, and spectral type between F8 and M1. HD 53706 fails the criteria due to the large error on its parallax, while HD 53680 satisfies them.
The two stars are also on the Anglo-Australian Telescope sample, which has found that they are stable to 4.5 and 2.9 m/s, respectively. This excludes the presence of giant planets at separations of a few AU around either star.


HY Velorum

HY Velorum is a binary star system in the southern constellation of Vela. It is a dim star but visible to the naked eye with an apparent visual magnitude of 4.83. The distance to this system, as estimated from its annual parallax shift of , is 460 light years. HY Vel most likely forms a gravitationally bound pair with the magnitude 5.45 binary system KT Vel (HD 74535); both are members of the IC 2391 open cluster. As of 1998, HY Vel and KT Vel had an angular separation of along a position angle of 311°.
This is a single-lined spectroscopic binary system with an orbital period of 8.4 days and an eccentricity of 0.24. The visible component has an "a" sin "i" value of , where "a" is the semimajor axis and "i" is the (unknown) orbital inclination to the line of sight.
The primary is a slowly pulsating B-type star having at least three pulsational modes, with the dominant mode showing a frequency of 0.64472 cycles per day, corresponding to the catalogued period of 1.55106 days. It has a stellar classification of B3 IV, matching a B-type subgiant star.


Iota Ursae Majoris

Iota Ursae Majoris (ι Ursae Majoris, abbreviated Iota UMa, ι UMa), also named Talitha , is a star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of 3.14, making it visible to the naked eye and placing it among the brighter members of this constellation. Based upon parallax measurements, it is located at a distance of from the Sun.
Nomenclature.
"ι Ursae Majoris" (Latinised to "Iota Ursae Majoris") is the star's Bayer designation.
The star bore the traditional names "Talitha", "Talitha Borealis" and "Alphikra Borealis". "Talitha", (which was shared with Kappa Ursae Majoris) comes from the Arabic phrase (), mistranscription of (), which means "the third spring, or leap, of the ghazal". The term "Borealis" meaning "the north side" in Latin. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Talitha" for this star.
In Chinese, (), meaning "Three Steps", refers to an asterism consisting of ι Ursae Majoris, Kappa Ursae Majoris, Lambda Ursae Majoris, Mu Ursae Majoris, Nu Ursae Majoris and Xi Ursae Majoris. Consequently, the Chinese name for ι Ursae Majoris itself is (, ).
The star was also dubbed "Dnoces" ('Second,' backwards) after Edward H. White II, an Apollo 1 astronaut. The name was invented by his fellow astronaut Gus Grissom as a practical joke.
Stellar system.
The Iota Ursae Majoris system is composed of two sets of binary stars. The two binary systems orbit around each other once every 2,084 years. The apparent separation between the two binaries is rapidly decreasing as they follow their orbits. In 1841 when the B component was first discovered, they had a separation of 10.7 arcseconds, or at least 156 AU. By 1971 their separation had decreased to 4.5 arcseconds, or at least 66 AU. This system appears to be dynamically unstable with a high likelihood and may become disrupted on a time scale on the order of 105 years.
The brightest component is a white A-type subgiant. It is a member of a spectroscopic binary system whose components have an orbital period of 4,028 days. The companion, which has not been directly observed, is thought to be a white dwarf with a mass of .
The companion binary is composed of the 9th magnitude and 10th magnitude stars, both of which are red dwarfs. These two red dwarfs, designated Iota Ursae Majoris B and C respectively, orbit around each other with a period of 39.7 years, and are separated by roughly 0.7 arcseconds, or at least 10 AU. This pair may be the source of the X-ray emission detected from this system.


49 Arietis

49 Arietis is a single star in the northern constellation of Aries. "49 Arietis" is the Flamsteed designation. It is visible to the naked eye as a faint, white hued star with an apparent visual magnitude of 5.90. The star is located at a distance of about distant from Earth based on parallax.
This object is classified as an Am star, or non-magnetic chemically peculiar star of the CP1 class, which means the spectrum displays abnormal abundances of certain heavier elements. It has a stellar classification of kA2hA6mA7, which means it has the calcium K line of an A2 class star, the Hydrogen lines of an A6 star, and the metal lines of an A7 star. 49 Arietis has a moderately high rate of spin, showing a projected rotational velocity of 52 km/s, and is radiating 15 times the luminosity of the Sun from its photosphere at an effective temperature of 8,424 K.


NGC 7035 and NGC 7035A

NGC 7035 and NGC 7035A are a pair of interacting lenticular galaxies located around 400 to 430 million light-years away in the constellation of Capricornus. The main galaxy, NGC 7035 was discovered by astronomer Frank Muller in 1886.


Kappa Andromedae b

Kappa Andromedae b is a directly-imaged substellar object and likely superjovian-mass planet orbiting Kappa Andromedae, a young B9IV star in the Andromeda constellation, about 170 light years away. The companion's mass is roughly 13 times the mass of Jupiter. As early history on kappa And b is filled with debate over whether it is an exoplanet or a brown dwarf, some scientists have broadly described it as a "Super-Jupiter" object.
Discovery.
Kappa Andromedae b was discovered through near-infrared high-contrast imaging the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) survey at the Subaru Telescope, located atop Mauna Kea, Hawaii Follow-up Subaru observations taken between January and July 2012 and covering a wider wavelength range confirmed that Kappa Andromedae is gravitationally bound (not a background star) and had infrared colors consistent with a substellar (possibly planet-mass) companion.
Atmosphere, Orbital Properties.
The low resolution near-infrared spectrum of kappa And b, obtained by extreme adaptive optics system SCExAO with the CHARIS integral field spectrograph, is shaped by broad water and carbon monoxide absorption features. Moderate resolution Keck/OSIRIS spectroscopy resolve these lines. Based on comparisons to large libraries of spectra for other substellar objects, the companion likely has a spectral type of L0--L1: its sharp H-band (1.65 microns) shape is indicative of low surface gravity.
Empirical comparisons to well-characterized substellar objects suggest an effective temperature of 1700--2000K. Atmospheric modeling incorporating longer wavelength data favors the cooler end of this temperature range, while temperatures derived from Keck/OSIRIS spectra favor higher values of 1950-2100K. The atmosphere of kappa And b is likely filled by thick cloud deck extending to low atmospheric pressures. Analysis of the companion's spectrum yields a near-solar carbon-to-oxygen ratio(C/O ~ 0.70).
Kappa Andromedae b was first imaged at a projected separation of about 55 au; subsequent data sets recover the companion at smaller angular separations. While only a small portion of the companion's orbital phase has been covered, current limits suggest a semimajor axis likely greater than 75 au. Its eccentricity is fairly high (e ~ 0.7 or greater). The relative radial-velocity between it and its host star is -1.4 +/- 0.9 km/s.
System Age and Mass.
The masses of directly-imaged substellar objects (exoplanets and brown dwarfs) are usually not directly measured but are instead inferred by comparing their luminosities to predicted values for substellar evolution models. Thus, uncertainties in the system age translate into uncertainties in the object's mass. The discovery paper for Kappa Andromedae b argued that the primary's kinematics are consistent with membership in the Columba Association, which would imply a system age of 20-50 million years and a mass of about 12.8 Jupiter masses. These results were later questioned who argued that the primary star's position on the Hertzsprung-Russell diagram favors a much older age of 220±100 million years, provided that the star, Kappa Andromedae A, is not a fast rotator viewed pole-on. Direct measurements of the star later showed that Kappa Andromedae A is in fact a rapid rotator viewed pole-on and yield a best-estimated age of 47 million years favoring a mass between 13 and 30 jovian masses. A revised luminosity and detailed empirical comparisons with other substellar objects with known ages favor a mass of 13 Jupiter masses.
Classification and Formation.
The nature of Kappa Andromedae b has been long-debated, specifically whether it is a gas giant planet or a brown dwarf, an object massive enough to fuse deuterium but not protium. The Working Group on Extrasolar Planets of the International Astronomical Union adopted the deuterium-burning limit (set at 13 Jupiter masses) to separate planets (below this limit) and brown dwarfs (above it). However, later work has revealed many free-floating objects labeled as brown dwarfs but with inferred masses at or well below the deuterium-burning limit. Models indicate that the exact definition of the deuterium-burning further depends on the assumed metallicity of the object and the completeness of deuterium burning, ranging from 11 Jupiter masses for an extremely metal-rich object at 10% burning to over 16 Jupiter masses for a metal poor object burning 90% of its deuterium. Alternate criteria for separating planets from brown dwarfs abandon the deuterium-burning limit altogether, instead inferring an object's nature based on its mass ratio with respect to its primary and its separation.
Previous debate centered largely on the system age, since it determines inferred values for the companion mass and mass ratio with respect to its primary star. For the now-disfavored older age (220±100 million years), the inferred mass of the companion would be well above the deuterium-burning limit and its mass ratio would exceed 1%, best consistent with a brown dwarf. Younger ages inferred from possible membership in Columba, derived from direct measurements of the star, and consistent with kappa And b's spectral properties strongly favor masses near 13 Jupiter masses and a mass ratio below 1%. The companion's orbital plane may also be aligned with the rotation axis of the star. These lines of evidence support the classification of this object as a superjovian-mass planet.
Forming a planet in situ with kappa And b's properties is extremely challenging for standard core accretion models for jovian planet formation. Instead, planet formation by gravitational instability may be a viable mechanism for this companion. The companion's derived carbon to oxygen ratio, thought to be a diagnostic of the object's accretion environment, and the primary's subsolar metallicity may be evidence that kappa And b formed through a rapid formation process, like gravitational instability.


37 Librae

37 Librae is a single star in the southern zodiac constellation of Libra. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.61. The star is located 94 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +49 km/s.
This is an evolving subgiant star with a stellar classification of K1 III–IV, where the luminosity class indicates the spectrum displays blended traits of a subgiant and a giant star. It is an estimated 3.4 billion years old with 1.4 times the mass of the Sun. Having the supply of hydrogen at its core all but exhausted, the star is starting to expand; currently it has five times the girth of the Sun. It is radiating 13.5 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,836 K.


Tau Puppis

Tau Puppis (Tau Pup, τ Puppis, τ Pup) is a star in the southern constellation of Puppis. It has an apparent visual magnitude of +2.95 and is located at a distance of about from Earth. This is a spectroscopic binary star system, with the presence of the secondary component being revealed by the shifts of absorption lines in the spectrum resulting from the Doppler effect. The two components orbit each other with a period of 1,066.0 days (2.9 years) and a low eccentricity of 0.090.
The primary component of this system has a stellar classification of K1 III. A luminosity class 'III' indicates this has expanded into a giant star after exhausting the supply of hydrogen at its core and evolving away from the main sequence of stars like the Sun. The interferometry-measured angular diameter of this star, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 27 times the radius of the Sun. It appears to be rotating slowly, with a projected rotational velocity of . This gives a lower bound on the azimuthal velocity of rotation along the star's equator. Tau Puppis is radiating energy from its outer envelope at an effective temperature of around 4,500, giving it the orange hue of a cool, K-type star.
References.
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63 Ceti

63 Ceti is a star in the constellation of Cetus, located just over a degree south of the celestial equator. With an apparent magnitude of about 5.9, the star is barely visible to the naked eye (see Bortle scale) as a dim, orange-hued point of light. Parallax estimates put it at a distance of about 390 light years (129 parsecs) away from the Earth, and it is drifting further away with a radial velocity of 28 km/s.
63 Ceti has a spectral type of K0III, implying an aging K-type giant star. These types of stars are generally reddish-colored stars with spectral types from K to M, with radii that are 10 to 100 times larger than the Sun. 63 Ceti fits this description, with a radius about 11 times larger than the Sun, a mass of about 1.85 times the Sun, and an effective temperature of 4940 K. 63 Ceti is a red clump giant, indicating it is currently at the horizontal branch, a stage in stellar evolution, and is generating energy through core helium fusion. It is close to a billion years old and is radiating 64 times the luminosity of the Sun from its photosphere at an effective temperature of 4,940 K.


Delta Mensae

Delta Mensae (δ Mensae) is a binary star system in the southern constellation of Mensa. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.69. Based upon an annual parallax shift of 7.70 mas as seen from the Earth, it is 420 light years from the Sun.
The primary, designated component A, is a K-type giant star with a stellar classification of K2/3 III. The measured angular diameter of this star is , which, at the estimated distance of this system, yields a physical size of about 14 times the radius of the Sun. The star is radiating 92 times the Sun's luminosity from its photosphere at an effective temperature of 5,183 K. Its companion, component B, is an A-type star about 0.9 magnitudes fainter than the primary.
References.
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Zeta2 Lyrae

Zeta2 Lyrae is a single, white-hued star in the northern constellation of Lyra. It is a dim star that is just visible to the naked eye with an apparent visual magnitude of 5.74 An annual parallax shift of as seen from Earth provides a distance estimate of about 158 light years from the Sun. It is moving closer to the Sun with a radial velocity of −25 km/s.
This star has a stellar classification of F0 IVn, suggesting it is an F-type subgiant star that is evolving away from the main sequence as its supply of hydrogen at the core has been consumed. The "n" suffix indicates "nebulous" lines caused by its rotation. It is spinning rapidly with a projected rotational velocity of 212 km/s. This is giving the star an oblate shape with an equatorial bulge that is an estimated 29% larger than the polar radius. The star is radiating approximately 9.6 times the Sun's luminosity from the photosphere at an effective temperature of 7,000 K. It has 1.7 times the mass of the Sun, twice the Sun's radius, and is about 1.2 billion years old.
It is a suspected variable.


NGC 608

NGC 608 is a lenticular galaxy in the constellation Triangulum. It is estimated to be about 230 million light-years from the Milky Way. It has a diameter of approximately 130,000 light-years. NGC 608 was discovered on November 22, 1827 by astronomer John Herschel.


Beta Caeli

Beta Caeli (β Caeli, abbreviated to β Cae) is the Bayer designation for a star in the southern constellation of Caelum. It is a dim star but visible to the naked eye, having an apparent visual magnitude of 5.04. Based upon an annual parallax shift of 4.88 mas as seen from Earth, it is located 94 light years from the Sun. The star is moving away from the Sun with a radial velocity of +28.8 km/s.
This is a probable single-lined spectroscopic binary star system. The visible component has a stellar classification of F3 V or F3 IV, indicating it is either an F-type main-sequence star or a somewhat more evolved subgiant star, respectively. It has an estimated 1.3 times the mass of the Sun and about 1.3 times the Sun's radius. The star is 1.75 billion years old and has a high rate of spin with a projected rotational velocity of around 97.5 km/s.
The companion may be a brown dwarf or a low-mass star orbiting more than 3 AU from the primary. This object may be the source of the X-ray emission coming from the same location.


N Scorpii

N Scorpii (N Sco) is a blue giant star in the constellation Scorpius. Its apparent magnitude is 4.23. It was initially given the Bayer designation Alpha Normae by Lacaille but later moved from Norma to Scorpius.


NGC 7380

NGC 7380 is a young open cluster of stars in the northern circumpolar constellation of Cepheus, discovered by Caroline Herschel in 1787. The surrounding emission nebulosity is known colloquially as the Wizard Nebula, which spans an angle of . German-born astronomer William Herschel included his sister's discovery in his catalog, and labelled it H VIII.77. The nebula is known as S 142 in the 1959 Sharpless catalog (Sh2-142). It is extremely difficult to observe visually, usually requiring very dark skies and an O-III filter. The NGC 7380 complex is located at a distance of approximately from the Sun, in the Perseus Arm of the Milky Way.
The cluster spans ~ with an elongated shape and an extended tail. Age estimates range from 4 to 11.9 million years. At the center of the cluster lies DH Cephei, a close, double-lined spectroscopic binary system consisting of two massive O-type stars. This pair are the primary ionizing source for the surrounding H II region, and are driving out the surrounding gas and dust while triggering star formation in the neighboring region. Of the variable stars that have been identified in the cluster, 14 have been identified as pre-main sequence stars while 17 are main sequence stars that are primarily B-type variables.


NGC 2537

NGC 2537 is a blue compact dwarf galaxy in the constellation Lynx, located around 3 degrees NNW of 31 Lyncis. This is Arp 6 or Mrk 86. It belongs to the iE class of Blue Compact Dwarf (BCD) classification, which is described as galactic spectra with an underlying smooth elliptical Low Surface Brightness component with a superimposed "knotted" star formation component (Gil de Paz et al., 2000, Page 378 Astron. Astrophys. Suppl. Ser. 145).
It was long thought to be possibly interacting with IC 2233. However, this is now considered highly unlikely as radio observations with the Very Large Array showed the two galaxies lie at different distances.


66 Aquilae

66 Aquilae, abbreviated 66 Aql, is a fifth-magnitude star in the constellation of Aquila. "66 Aquilae" is its Flamsteed designation. It is visible to the naked eye, having an apparent visual magnitude of 5.44. The star shows an annual parallax shift of , which provides a distance estimate of around 730 light years. It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s. The motion of the star over time suggests some displacement, which may indicate it is a close binary system.
This is an aging giant star with a stellar classification of K5 III, which indicates it has exhausted the supply of hydrogen at its core and expanded off the main sequence. The measured angular diameter of this star, after correcting for limb darkening, is . At its estimated distance, this yields a physical size of roughly 59 times the radius of the Sun. It is radiating 635 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,040 K, giving the star an orange hue.
References.
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Sh2-54

Sh2-54 is an extended bright nebula in the constellation of Serpens.
In its core there are many protostars and many infrared sources; some of these sources, like IRAS 18151−1208, are most probably very young high-mass stars. The older star population in this region has an average age of 4-5 million years, and its components are grouped in the open cluster NGC 6604.
Sh2-54 belongs to an extended nebulosity that includes also the Eagle Nebula and the Omega Nebula. The young high-mass stars of this region constitute the Serpens OB1 and Serpens OB2 OB association.


HD 37756

HD 37756 is a binary star system in the equatorial constellation of Orion, positioned less than a degree to the north of the bright star Alnitak. It has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.95. The system is located at a distance of approximately 900 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +26 km/s. It is a member of the OB1b subgroup of the Orion OB1 Association.
The binary nature of this system was identified by E. B. Frost in 1904. It is a double-lined spectroscopic binary with an orbital period of 27.15 days and a high eccentricity of 0.74. The spectrum matches a massive B-type main-sequence star with a stellar classification of B3V. The secondary is luminous enough to interfere with measurements of the primary spectrum. It is a suspected Cepheid variable with a period of 0.37968 days and an amplitude of 0.03 magnitude in the B band of the UBV photometric system. The system is a candidate eclipsing binary with a minimum dip of 0.04 in visual magnitude during each orbit.


Kappa Cephei

Kappa Cephei, Latinized from κ Cephei, is a binary star system in the northern circumpolar constellation of Cepheus. It is visible to the naked eye as a faint, blue white-hued point of light with an apparent visual magnitude is 4.39. The system is located approximately 323–326 light years distant from the Sun, based on parallax.
The two gravitationally-bound members of this system had an angular separation of along a position angle of 120°, as of 2015. The primary, designated component A, has a stellar classification of B9III, matching a blue giant. The magnitude 8.34 secondary, component B, is an A-type main-sequence star of class A7V. A third star of 10th magnitude, BD+77 763, is listed as component C in the Washington Double Star Catalog although it is a background object unrelated to the other two.


Kappa Serpentis

Kappa Serpentis, Latinised from κ Serpentis, is a single, red-hued star in the constellation Serpens, in its head (Serpens Caput). It has the proper name Gudja and the Flamsteed designation 35 Serpentis. This star is visible to the naked eye with an apparent visual magnitude of +4.09. It is located approximately 382 light years from the Sun, based on parallax, and is drifting closer with a radial velocity of −38 km/s.
This object is an aging red giant star with a stellar classification of M0.5III. After exhausting the supply of hydrogen at its core, the star cooled and expanded off the main sequence, and now has around 51 times the Sun's radius. It is radiating 628 times the luminosity of the Sun from its photosphere at an effective temperature of 4,033 K. This is a suspected variable star.
Nomenclature.
"κ Serpentis" (Latinised to "Kappa Serpentis") is the star's Bayer designation.
The star bore the traditional name in the culture of the Wardaman people of the Northern territory of Australia, meaning 'water goanna'. In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name "Gudja" for this star on 10 August 2018 and it is now so included in the List of IAU-approved Star Names.


Gliese 357

GJ 357 (also designated Gliese 357) is an M-type main sequence star with an unusually low starspot activity. It is located 31 light-years from the Solar System,
Planetary system.
The star has three confirmed exoplanets in its orbit, one of which, GJ 357 d, is considered to be a "super-Earth" within the circumstellar habitable zone. The system is part of the Hydra constellation.


Kepler-45

Kepler-45, formerly known as KOI-254, is a star in the northern constellation of Cygnus. It is located at the celestial coordinates: right ascension , declination . With an apparent visual magnitude of 16.88, this star is too faint to be seen with the naked eye.
The star is exhibition a strong starspot activity, with 4.1% of its surface covered by starspots.
Planetary system.
The "Hot Jupiter" class planet Kepler-45b, discovered in February 2011, is unusually massive for the M-class parent star. Its orbit is aligned within 11 degrees of rotational axis of the star.
The planet is strongly suspected to have an optically thick rings, because planetary shadow appears to be elongated.


NGC 7673

NGC 7673 is a disturbed spiral galaxy located in the constellation Pegasus. The galaxy has recently experienced intense star formation activity and may therefore be referred to as a starburst galaxy.


Iota Draconis b

Iota Draconis b, formally named Hypatia (pronounced or ), is an exoplanet orbiting the K-type giant star Iota Draconis about 101.2 light-years (31 parsecs, or nearly km) from Earth in the constellation Draco. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. It was the first planet discovered orbiting a giant star.
Physical characteristics.
Mass, radius and temperature.
Iota Draconis b is a "super-Jupiter" a planet that has mass larger than that of the gas giants Jupiter and Saturn. It has a blackbody temperature of . It has an estimated mass of around 8.82 and a potential radius of around 12 based on its mass, since it is more massive than Jupiter.
Host star.
The planet orbits a (K-type) giant star named Iota Draconis. The star has exhausted the hydrogen supply in its core and is currently fusing helium. The star has a mass of 1.82 and a radius of around 12 . It has a surface temperature of 4545 K and is around 800 million years old based on its evolution. Although much younger than the Sun, the higher mass of this star correlates to a faster evolution, leading to the host star having already departed from the main sequence. When on the main sequence, Iota Draconis was probably a Class A star with surface temperature between 7,400 and 10,000K. In comparison, the Sun is about 4.6 billion years old and has a surface temperature of 5778 K.
The star's apparent magnitude, a measure of how bright it appears from Earth, is 3.31. Therefore, Iota Draconis can be seen with the naked eye.
Orbit.
Iota Draconis b orbits its star with nearly 55 times the Sun's luminosity (55 ) every 511 days at an average distance of 1.275 AU (compared to Mars' orbital distance from the Sun, which is 1.52 AU) It has a very eccentric orbit, with an eccentricity of 0.7124.
Name.
Following its discovery the planet was designated Iota Draconis b. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced that the winning name for this planet was Hypatia. The winning name was submitted by Hypatia, a student society of the Physics Faculty of the Universidad Complutense de Madrid, Spain. Hypatia was a famous Greek astronomer, mathematician, and philosopher.
Discovery.
Discovered in 2002 during a radial velocity study of K-class giant stars, its eccentric orbit aided its detection, as giant stars have pulsations which can mimic the presence of a planet.


Kepler-90e

Kepler-90e is an exoplanet orbiting the star Kepler-90, located in the constellation Draco. It was discovered by the "Kepler" telescope in October 2013. It orbits its parent star at only 0.42 astronomical units away, and at its distance it completes an orbit once every 91.94 days.


Omicron Capricorni

Omicron Capricorni (ο Capricorni) is a wide binary star system in the constellation Capricornus. The brighter component has an apparent visual magnitude of +5.94, which is near the lower limit on stellar brightness that still can be seen with the naked eye. Based upon an annual parallax shift of 15.07 mas as seen from Earth, this system is located roughly 220 light years from the Sun. Large but uncertain discrepancies in the parallax measurements from Hipparcos may indicate, weakly, that there is a third, unseen companion in the system.
Both visible components are white-hued A-type main-sequence stars. The primary, component A, sometimes called ο1 Capricorni, has an apparent magnitude of +5.94, while the companion, component B or ο2 Capricorni, has an apparent magnitude of +6.74. The two stars are currently separated by 21.91 arcseconds − corresponding to a projected separation of around 2,100 AU. At the estimated age of around 118 million years old, both components are spinning rapidly: component A has a projected rotational velocity of 276 km/s, while component B is 136 km/s.


24 Comae Berenices

24 Comae Berenices is a triple star system in the northern constellation of Coma Berenices. It is visible to the naked eye, with the brightest component being an orange-hued star with an apparent visual magnitude of 5.03. The system is located at a distance of approximately 269 light years from the Sun based on parallax, and is drifting further away with radial velocities of 3–5 km/s.
This system can be resolved in a telescope as a pair of stars with an angular separation of along a position angle of 272°, as of 2018. They share a common motion through space and thus appear to be physically associated, with a wide projected separation of or greater. If they are bound in an orbit, the estimated period is approximately 28,000 years.
The brighter member of this system is an aging giant or bright giant star with a stellar classification of K0II-III. It has exhausted the supply of hydrogen at its core and expanded to 20 times the girth of the Sun. This is a suspected variable that has been recorded ranging in brightness from magnitude 4.98 down to 5.06. The star is radiating 173 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,688 K.
The fainter component at magnitude 6.57 is a double-lined spectroscopic binary with an orbital period of 7.33 days and an eccentricity of 0.26. The primary member of this pair is an A-type main-sequence star with a stellar classification of A9V. It is a metallic-lined Am star with 2.9 times the radius of the Sun. The star is radiating 24 times the Sun's luminosity from its photosphere at an effective temperature of 7,476 K. It has a relatively low projected rotational velocity of under 20 km/s, and it is suspected the rotations of this binary system may be synchronized. The system is a source for X-ray emission, which is most likely coming from the secondary.


BW Vulpeculae

BW Vulpeculae or BW Vul, is a variable star in the northern constellation of Vulpecula. It is near the lower limit of visibility to the naked eye with a typical apparent visual magnitude of 6.54. Based on an annual parallax shift of , the distance to BW Vul is about 2,800 light years. It is moving closer to the Earth with a baseline heliocentric radial velocity of around −6 km/s.
This is a B-type giant star with a stellar classification of B2 IIIv, where the 'v' suffix indicates variability in spectral features. Various authors have printed mass estimates ranging from 11 to 14 times the mass of the Sun, although Tetzlaff et al. (2011) gives a mass of just . It is about 3.4 million years old and is spinning with a projected rotational velocity of 24 km/s. The star is typically radiating 515 times the Sun's luminosity from its photosphere at an effective temperature of 23,014 K.
The variability of this star was announced in 1937, at the 58th Meeting of the American Astronomical Society by Canadian astronomer, Robert Methven Petrie. It is a Beta Cephei variable that ranges between magnitudes 6.44 and 6.68 over a period of 4.8 hours. For unknown reasons, the periodicity of the star has undergone sudden changes, followed by long periods of stability. BW Vul is one of the most extreme β Cephei stars in terms of variability of light and radial velocity. This is hypothesized as being due to the star's relatively high metallicity, meaning the abundance of elements other than hydrogen and helium. A distinctive feature of its radial velocity cycle is a unique "standstill" feature, which is caused by a shockwave generated by infall of material from a previous cycle.


NGC 6559

NGC 6559 is a star-forming region located at a distance of about 5000 light-years from Earth, in the constellation of Sagittarius, showing both emission (red) and reflection (bluish) regions.


NGC 439

NGC 439 is a lenticular galaxy of type SAB0^-(rs)? located in the constellation Sculptor. It was discovered on September 27, 1834 by John Herschel. It was described by Dreyer as "pretty bright, small, round, gradually brighter middle."


Gliese 877

Gliese 877 (GJ 877 / HIP 113229 / LHS 531) is a red dwarf located in the southern constellation of Octans, near the boundary with Indus.
Gliese 877's bolometric luminosity is just 2.3% of our sun's. It shines with an apparent magnitude of +10.22, so it cannot be seen with the naked eye. Nevertheless, it is considerably brighter than other red dwarfs, such as Proxima Centauri, the closest red dwarf to our Solar System; in particular, it is almost 14 times more luminous than Proxima. Of spectral type M3V, its effective temperature is 3390 K. It does not appear to be a variable star.
Gliese 877 is 28.1 light years from the Solar System. Known stars close to it are β Hydri and ζ Tucanae, respectively 4.5 and 6.2 light years.


Omicron Scorpii

Omicron Scorpii (ο Sco, ο Scorpii) is a star in the zodiac constellation of Scorpius. With an apparent visual magnitude of +4.57, it is visible to the naked eye. Parallax measurements indicate a distance of roughly 900 light years. It is located in the proximity of the Rho Ophiuchi dark cloud.
This is a white A-type bright giant with a stellar classification of A4II/III. It is one of the brighter members of this rare class of stars, making it of interest for study. Omicron Scorpii has about eight times the mass of the Sun, fifteen times the radius, and is roughly 40 million years old. The star is radiating around 3,200 times the luminosity of the Sun from its outer atmosphere at an effective temperature of about 8,128 K. It does not display an infrared excess due to circumstellar dust or a possible infrared-bright companion, but the light from this star is subject to extinction from interstellar dust.
Omicron Scorpii was occasionally mentioned as a possible member of the Upper Scorpius sub-group in the Scorpius-Centaurus OB association during the 20th century. However, it does not appear in more recent membership lists for this group due to its small proper motion and small trigonometric parallax as measured by Hipparcos. This suggests that it is a background star unrelated to Scorpius-Centaurus.


HD 70573

HD 70573 is a variable star in the equatorial constellation of Hydra. At a mean apparent visual magnitude of +8.71, this yellow-hued star is too dim to be visible to the naked eye. Based upon parallax measurements, it is located at a distance of 193 light years from the Sun, and is drifting further away with a radial velocity of 20.5 km/s. It is a candidate member of the proposed Hercules-Lyra Association of co-moving stars, although this membership is disputed.
This is a G-type main-sequence star with a stellar classification of G1/2V. It is a BY Draconis variable that ranges in brightness from magnitude 8.66 down to 8.77 with a rotationally-modulated period of 3.296 days. This is a young star with an age of around 60 million years and a projected rotational velocity of 15 km/s. It has about the same mass, size, and luminosity as the Sun.
Planetary system.
On March 19, 2007, an extrasolar planet was announced, having been discovered by the radial velocity method. This is thus far (as of 2007) the youngest host star discovered to have an orbiting planet. The system displays an infrared excess, which matches the black body signature of a debris disk orbiting from the host star with a mean temperature of 60 K.


NGC 449

NGC 449 is a spiral galaxy of type (R')S? located in the constellation Pisces. It was discovered on November 11, 1881 by Édouard Stephan. It was described by Dreyer as "very faint, very small, round, very little brighter middle, very faint star involved."


Upsilon Librae

Upsilon Librae (υ Lib, υ Librae) is the Bayer designation for a double star in the zodiac constellation Libra. With an apparent visual magnitude of 3.628, it is visible to the naked eye. The distance to this star, based upon an annual parallax shift of 14.58, is around 224 light years. It has a magnitude 10.8 companion at an angular separation of 2.0 arc seconds along a position angle of 151°, as of 2002.
The brighter component is an evolved K-type giant star with a stellar classification of K3 III. The measured angular diameter, after correction for limb darkening, is . At the estimated distance of the star, this yields a physical size of about 31.5 times the radius of the Sun. It has 1.67 times the mass of the Sun and radiates 309 times the solar luminosity from its outer atmosphere at an effective temperature of 4,135 K. The star is about three billion years old.
References.
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Theta Pegasi

θ Pegasi, Latinized as Theta Pegasi, is a single star in the equatorial constellation of Pegasus, lying about 7.5 degrees southwest of Enif. It has the traditional name Biham , and the Flamsteed designation 26 Pegasi. This object is visible to the naked eye as a white-hued point of light with an apparent visual magnitude of +3.52. The system is located 92 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −8 km/s.
This object an A-type main-sequence star with a stellar classification of A2V. It is 448 million years old with a high rate of spin, showing a projected rotational velocity of 136 km/s. This star has 2.14 times the mass of the Sun and 2.6 times the Sun's radius. It is radiating 25 times the luminosity of the Sun from its outer envelope at an effective temperature of 7,951 K. The star appears to display a slight infrared excess.
Nomenclature.
"θ Pegasi" (Latinised to "Theta Pegasi") is the star's Bayer designation.
It bore the traditional name "Biham" or "Baham" from the Arabic phrase "s'ad al Biham" "Lucky Stars of the Young Beasts". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name "Biham" for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.
In Chinese, (), meaning "Rooftop", refers to an asterism consisting of Theta Pegasi, Alpha Aquarii and Epsilon Pegasi. Consequently, the Chinese name for Theta Pegasi itself is (, .)


Andromeda XVIII

Andromeda XVIII, discovered in 2008, is a dwarf spheroidal galaxy (has no rings, low luminosity, much dark matter, little gas or dust), which is a satellite of the Andromeda Galaxy (M31). It is one of the 14 known dwarf galaxies orbiting M31. It was announced in 2010 that the orbiting galaxies lie close to a plane running through M31's center.


Y Sextantis

Y Sextantis, abbreviated as Y Sex, is a variable star system in the equatorial constellation of Sextans. The system is invisible to the naked eye with a mean apparent visual magnitude of 9.88. It is located roughly at 1,300 light years from the Sun based on parallax.
The variability of this system was first announced by C. Hoffmeister in 1934. It was determined to be a short period, strongly-interacting eclipsing binary system. Observations of the light variations up until 1979 were used by G. Hill to generate orbital properties, providing an orbital inclination of .
This is a W Ursae Majoris variable eclipsing contact binary star system, whose two component stars share a common outer layer. Because the two components share their outer layers as the components of W Ursae Majoris do, they have the same stellar classification, and are classified as yellow F-type main sequence dwarfs. The components take 0.419822800 days (roughly 10 hours) to revolve around common barycentre. Orbital period variations would suggest the presence of additional perturbing objects, one of them likely substellar.
Perturbing third (and fourth?) body.
Orbital period variations suggest the presence of one more perturbing unseen object. The authors He & Qian have estimated two possible orbital periods and minimum masses for unseen companions: the former cyclic oscillation would occur every 51.22 years (with amplitude of 0.0218 days) being caused by a low-mass stellar companion (likely a M dwarf star), whereas the latter would consist in a 32.1 years period and the unseen object could likely be substellar.


Upsilon2 Eridani

Upsilon² Eridani (υ² Eridani, abbreviated Upsilon² Eri, υ² Eri), officially named Theemin , is a star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.8. Based upon parallax measurements obtained during the Hipparcos mission, it is approximately 66 parsecs (214 light-years) from the Sun.
This is an evolved red clump giant star with a stellar classification of G8+ III. The measured angular diameter is 2.21 mas. At the star's distance, this yields a physical size of around 16 times the radius of the Sun. It radiates 138 times the solar luminosity from its outer atmosphere at an effective temperature of 5074 K.
Nomenclature.
υ² Eridani (Latinised to "Upsilon² Eridani") is the star's Bayer designation.
It bore the traditional name "Theemin" (also written as "Theemim" and "Beemin"). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name "Theemin" for this star on February 1, 2017 and it is now so now so included in the List of IAU-approved Star Names.
In the Almagest, Ptolemy called it "hē kampē", "the bend in the river;" Arab writers corrupted this to "bhmn", later becoming "beemin", "beemun" in the West. Then, its etymology was incorrectly derived from Hebrew תאומים ("te'omim"), meaning "twins," producing "Theemin".
In Chinese, (), meaning "Celestial Orchard", refers to an asterism consisting of Upsilon² Eridani, Chi Eridani, Phi Eridani, Kappa Eridani, HD 16754, HD 23319, Theta Eridani, HD 24072, HD 24160, Upsilon⁴ Eridani, Upsilon³ Eridani and Upsilon¹ Eridani. Consequently, the Chinese name for Upsilon² Eridani itself is (, ).
References.
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ET Virginis

ET Virginis is a single, red-hued star in the equatorial constellation of Virgo. It can be viewed with the naked eye, having an apparent visual magnitude of 4.91. Based upon an annual parallax shift of , it is located 560 light years away. It is moving further from the Earth with a heliocentric radial velocity of +18.6 km/s, having come within of the Sun around 6.3 million years ago.
This is an evolved red giant star with a stellar classification of M2 IIIa. It is a semiregular variable star of subtype SRB with a magnitude that ranges from a high of 4.80 down to 5.00. The measured angular diameter of this star, after correcting for limb darkening, is . At its estimated distance, this yields a physical size of 88 times the radius of the Sun.
References.
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U Centauri

The designations U Centauri and u Centauri refer to two different stars in the constellation Centaurus.


S Scuti

S Scuti is a carbon star located in the constellation Scutum. Parallax measurements by Hipparcos put it at a distance of approximately 1,300 light-years (390 parsecs). Its apparent magnitude is 6.80, making it visible to the naked eye only under excellent conditions.
S Scuti is a semiregular variable star. Its class is SRb, and its pulsation cycle lasts 148 days. It has a radius of . S Scuti is also surrounded by a roughly spherical shell of dust. The shell was known earlier from its carbon dioxide emission lines. The total mass of the dust is .


HD 32450

HD 32450, also known as Gliese 185 is a binary star in the constellation Lepus. It is located about 28 light years from the Solar System. This star will make its closest approach to the Sun in roughly 350,000 years, when it comes within .


TrES-4b

TrES-4b is an extrasolar planet, and one of the largest exoplanets ever found, after WASP-12b, WASP-17b, CT Chamaeleontis b (though the latter may be a brown dwarf) and GQ Lupi b. It was discovered in 2006, and announced in 2007, by the Trans-Atlantic Exoplanet Survey, using the transit method. It is approximately away orbiting the star GSC 02620-00648, in the constellation Hercules.
Orbit.
A 2008 study concluded that the GSC 06200-00648 system (among others) is a binary star system allowing even more accurate determination of stellar and planetary parameters.
TrES-4 orbits its primary star every 3.543 days and eclipses it when viewed from Earth.
The study in 2012, utilizing a Rossiter–McLaughlin effect, have determined the planetary orbit is probably aligned with the equatorial plane of the star, misalignment equal to 6.3°.
Physical characteristics.
The planet is slightly less massive as Jupiter (0.919 ± 0.073 ) but its diameter is 79.9% larger; it was considered the largest planet ever found at the time, giving it an average density of only about 1/3 gram per cubic centimetre, approximately the same as Saturn's moon Methone. This made TrES-4 both the largest known planet and the planet with the lowest known density at the time of its discovery.
TrES-4's orbital radius is 0.05091 AU, giving it a predicted surface temperature of about 1782 K. This by itself is not enough to explain the planet's low density, however. It is not currently known why TrES-4 is so large. The probable causes are the proximity to a parent star that is 3–4 times more luminous than the Sun as well as the internal heat within the planet.


Kepler-70b

Kepler-70b (formerly known as its Kepler Object of Interest designation "KOI-55.01"; sometimes listed as KOI-55 b) is one of two postulated exoplanets orbiting the subdwarf B star (sdB) Kepler-70. The other planet is Kepler-70c, and both planets (if they exist) orbit very close to their host star.
However, later research suggests that the two exoplanets probably do not exist, and that "pulsation modes visible beyond the cut-off frequency of the star" were a more likely explanation for the signals believed to indicate exoplanets. This is not proven with certainty one way or the other.
If it exists, Kepler-70b completes one orbit around its star in just 5.76 hours, so is an ultra-short period planet. It is also the hottest known exoplanet as of mid-2017, with a surface temperature of several thousand Kelvin. Its density is 5500 kg/m3 which is not much different from Earth.
Characteristics.
Mass, radius and temperature.
Kepler-70b is likely a rocky exoplanet with a mass of 0.44 and a radius of 0.76 . It has a surface temperature of over seven thousand Kelvin, the hottest known surface temperature of any exoplanet. While the precise temperature is not known, it is expected to be hotter than the surface of the Sun.
Orbit.
The exoplanet has an orbit period shorter than any exoplanet known to date, with an orbital period of 5.76 hours (345 minutes). This comes in second to the exoplanet PSR 1719-14 b, which, coincidentally, orbits a stellar remnant, much like the planets of Kepler-70.
Host star.
The host star, Kepler-70 (also formally known as "KOI-55", "2MASS J19452546+4105339" or "KIC 5807616"), is a subdwarf B-type star that has left its red giant stage of its lifetime – according to the Extrasolar Planets Encyclopedia – about ago. It has a surface temperature of 27730 ± 270 K, nearly 6 times as hot as the surface temperature of the Sun, which has a surface temperature of 5778 K. The star has a mass of 0.496 and a radius of 0.203 It is expected to become a white dwarf in the future, after fusing the remaining helium in its core, and shrink in size to around the size of the Earth.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 14.87. Therefore, Kepler-70 is too dim to be seen with the naked eye.
Encounters.
Kepler-70c passes away from Kepler-70b during their closest approach, possibly causing tidal forces against each other. This is currently the closest recorded approach between planets.
Cultural impact.
According to the main author of the paper in "Nature" which announced the discovery of the two planets, Stephane Charpinet, the two planets "probably plunged deep into the star's envelope during the red giant phase, but survived." However, this is not the first sighting of planets orbiting a post-red giant star – numerous pulsar planets have been observed, but no planet has been found with such a short period around any star, whether or not on the main sequence.
Origins.
The two planets were most likely gas giants which spiraled inward toward their host star, which subsequently became a red giant, vaporizing much of the planets except for parts of their solid cores, which are now orbiting the Subdwarf B star. Another theory is that only one gas giant spiralled inward into the star, and that its core fragmented inside the red giant after engulfment, with the current planets being the large core fragments.


HD 35520

HD 35520 is a single star in the northern constellation of Auriga. It has a white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.92. The distance to this star is approximately 2,200 light years based on parallax. The radial velocity for the star is, as yet, poorly constrained.
This is an aging chemically peculiar star, or Ap star, in the giant stage of its evolution, with a stellar classifications of A1 III and A1p. The spectrum displays abundance anomalies of helium and silicon. It has been classed as a shell star and has a relatively high projected rotational velocity for its class of 80 km/s. The star has expanded to 23 times the radius of the Sun and it is radiating 1,635 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 7,645 K.


Mu2 Cancri

Mu2 Cancri is a solitary, yellow-hued star in the zodiac constellation of Cancer. It is visible to the naked eye with an apparent visual magnitude of +5.30. Based upon an annual parallax shift of 42.94 mas as seen from Earth, this star is located around 76.0 light years from the Sun. Mu2 Cancri will make its closest approach in about 600,000 years when it passes at a distance of .
At the estimated age of 5.6 billion years, it is an evolving G-type subgiant star with a stellar classification of G2 IV. It has 1.2 times the mass of the Sun and 1.8 times the Sun's radius. Mu2 Cancri has relatively high metallicity − what astronomers term the abundance of elements other than hydrogen and helium − having a 29% higher abundance compared to the Sun. It is radiating 3.45 times the Sun's luminosity at an effective temperature of 5,809 K.


Sigma Cancri

The Bayer designation Sigma Cancri (σ Cnc / σ Cancri) is shared by three star systems, in the constellation Cancer:
The above correspondence between Flamsteed and Bayer designations is the modern one, which is based on the "Atlas Coelestis Novus" published by Eduard Heis in 1872. An alternate correspondence sometimes encountered, for instance in the 1835 astronomical catalogue of Thomas Brisbane, is:
Johann Bayer's Uranometria places the sigma between these two groups of stars, making proper association uncertain.


Omicron Serpentis

Omicron Serpentis (ο Ser, ο Serpentis) is a solitary star in the Serpens Cauda (tail) section of the equatorial constellation Serpens. Based upon an annual parallax shift of 18.83 mas as seen from Earth, it is located around 173 light years from the Sun. The star is visible to the naked eye with a base apparent visual magnitude of +4.26.
This is a white-hued A-type main sequence star with a stellar classification of A2 Va. It is located on the lower instability strip and is classified as a Delta Scuti type variable star. The apparent magnitude of the star varies in the range 4.26−4.27 with a period of 76 minutes, or 0.053 days.
The star has an estimated 2.13 times the mass of the Sun and about 2.2 times the Sun's radius. It is about half a billion years old and is spinning with a projected rotational velocity of 112.6 km/s. Omicron Serpentis is radiating 42.6 times the solar luminosity from its photosphere at an effective temperature of 8,972 K.


Eta Cygni

Eta Cygni (η Cygni) is a star in the northern constellation of Cygnus. It is visible to the naked eye with an apparent visual magnitude of 3.889. The star lies along the main body of the constellation, about midway between Gamma Cygni and Albireo. Based upon an annual parallax shift of 24.17 mas, it is located 135 light years from the Sun.
At an age of about 3.3 billion years, this is an evolved red clump giant star with a stellar classification of K0 III. It is presently on the horizontal branch and is generating energy through the nuclear fusion of helium at its core. The star has about 1.59 times the mass of the Sun and has expanded to 11 It radiates 52.5 times the solar luminosity from its outer atmosphere at an effective temperature of 4,783 K.
Eta Cygni has five visual companions, of which only component B appears to be physically associated. This magnitude 12.0 star lies at an angular separation of 7.80 arc seconds along a position angle of 206°, as of 2007.


AO Serpentis

AO Serpentis is an eclipsing binary star system in the Serpens Caput segment of the Serpens constellation. It is invisible to the naked eye with a typical apparent visual magnitude of 11.04. Variable star observers record a peak magnitude of 10.7, dropping to 12.0 during the primary eclipse and 10.8 from the secondary eclipse. The distance to this system is approximately 1,530 light years based on parallax.
This system was discovered by C. Hoffmeister to be an Algol-type eclipsing binary in 1935. The following year, P. Guthnick and R. Prager reported a brightness variation between 10.5 and 12.0. In 2004, S. -L. Kim and associates determined that one of the components of this system is pulsating with a short period.
This is a semi-detached binary star system with the secondary component completely filling its Roche lobe while the primary is 61% full. It has an orbital period of and a semimajor axis of just 5.6 times the radius of the Sun. The orbital plane is inclined by an angle of 90° to the line of sight, causing the secondary component to be completely eclipsed once per orbit. The orbital period shows long-term cyclic variations, changing by up to 0.0051 days every 17.32 years. This may be due to magnetic activity cycles or the influence of a third body. The orbital period as a whole is steadily decreasing at the rate of due to loss of mass and angular momentum by the system.
The physical properties of the stellar components can be explained by a mass transfer. At some point in the past, mass flowed from the (at the time) more massive and evolved secondary component. This has left the primary as an A-type main-sequence star while the secondary is less massive but overly large. The hotter primary component is a Delta Scuti variable that is undergoing radial pulsation with a dominant frequency of 21.852 days−1 and a secondary frequency of 23.484 days−1.


KU Hydrae

KU Hydrae is a binary star in the constellation Hydra. The primary star is an Alpha2 Canum Venaticorum variable with its apparent magnitude varying from 0.05 magnitudes over a period of 33.97 days.
This star was discovered to be a visual binary star by Robert Grant Aitken in 1906 and was given the double star designation A 1342. Additional measurements of the position angle and angular separation showed a rapid orbital motion.