3 Herculis
3 Herculis Facts
3 Herculis's star type is giant star that can be located in the constellation of Serpens. The description is based on the spectral class.
3 Herculis is not part of the constellation outline but is within the borders of the constellation.
Based on the spectral type (K0III:) of the star, the star's colour is orange to red .
3 Herculis's Alternative Names
The Gould star designation is one that was designed by American astronomer, Benjamin Apthorp Gould. Gould stars are predominantly in the Southern and Equatorial constellations but do appear in northern constellations such as Bootes and Orion. The star has the designation 34 Cap G. Serpentis. There are no stars with a Gould designation in Ursa Major for example.
Location of 3 Herculis
The location of the giant star in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the object is compared to the celestial equator and is expressed in degrees. For 3 Herculis, the location is 16h 00m 51.16 and +04° 25` 37.8 .
Radial Velocity and Proper Motion of 3 Herculis
All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving 73.99 ± 0.27 milliarcseconds/year towards the north and -42.18 ± 0.36 milliarcseconds/year east if we saw them in the horizon.
The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -7.85 km/s with an error of about 0.22 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.
3 Herculis Luminosity
Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 32.14 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.
Physical Properties (Colour, Temperature) of 3 Herculis
3 Herculis Colour and Temperature
3 Herculis has a spectral type of K0III:. This means the star is a orange to red giant star. The star has a B-V Colour Index of 1 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,849 Kelvin.
3 Herculis Radius
Radius has been calculated as being 6.66 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 4,635,203.80.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 6.82. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -0.30 with an error value of 0.02 Fe/H with the Sun has a value of 1 to put it into context.
3 Herculis Apparent and Absolute Magnitudes
3 Herculis has an apparent magnitude of 5.82 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 1.49 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.44. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.
Distance to 3 Herculis
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 13.62 which gave the calculated distance to 3 Herculis as 239.47 light years away from Earth or 73.42 parsecs. It would take a spaceship travelling at the speed of light, 239.47 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.
In 2007, Hipparcos data was revised with a new parallax of 13.32 which put 3 Herculis at a distance of 244.87 light years or 75.08 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.
The star's Galacto-Centric Distance is 7,344.00 Parsecs or 23,953.44 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.
Additional 3 Herculis Facts and Figures
Primary / Proper / Traditional Name 3 Herculis
Alternative Names HD 143553, HIP 78442, 34 Cap G. Serpentis, BD+04 3096
Spectral Type K0III:
Star Type Giant Star
Colour Orange to Red
Constellation Serpens
Absolute Magnitude 1.49 / 1.44
1997 Distance from Earth 13.62 Parallax (milliarcseconds)
73.42 Parsecs
Proper Motion Dec. 73.99 ± 0.27 milliarcseconds/year
Proper Motion RA. -42.18 ± 0.36 milliarcseconds/year
B-V Index 1.00
Radial Velocity -7.85 ± 0.22 km/s
Iron Abundance -0.30 ± 0.02 Fe/H
Stellar Luminosity (Lsun) 32.14
Effective Temperature 4,849 Kelvin
Unukalhai (Alpha Serpentis)
Beta Serpentis (Beta Serpentis)
Gamma Serpentis (Gamma Serpentis)
Delta Serpentis (Delta Serpentis)
Nulla Pambu (Epsilon Serpentis)
10 Cap G. Serpentis
10 Cau G. Serpentis