of the sky, Apus ranks 67th of the 88 modern constellations by area. Its position in the Southern Celestial Hemisphere means that the whole constellation is visible to observers south of 7°N. It is bordered by Ara, Triangulum Australe and Circinus to the north, Musca and Chamaeleon to the west, Octans to the south, and Pavo to the east. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Aps". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of six segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −67.48° and −83.12°. Features Stars Lacaille gave twelve stars Bayer designations, labelling them Alpha through to Kappa, including two stars next to each other as Delta and another two stars near each other as Kappa. Within the constellation's borders, there are 39 stars brighter than or equal to apparent magnitude 6.5. Beta, Gamma and Delta Apodis form a narrow triangle, with Alpha Apodis lying to the east. The five brightest stars are all red-tinged, which is unusual among constellations. Alpha Apodis is an orange giant of spectral type K3III located 430 ± 20 light-years away from Earth, with an apparent magnitude of 3.8. It spent much of its life as a blue-white (B-type) main sequence star before expanding, cooling and brightening as it used up its core hydrogen. It has swollen to 48 times the Sun's diameter, and shines with a luminosity approximately 928 times that of the Sun, with a surface temperature of 4312 K. Beta Apodis is an orange giant 149 ± 2 light-years away, with a magnitude of 4.2. It is around 1.84 times as massive as the Sun, with a surface temperature of 4677 K. Gamma Apodis is a yellow giant of spectral type G8III located 150 ± 4 light-years away, with a magnitude of 3.87. It is approximately 63 times as luminous the Sun, with a surface temperature of 5279 K. Delta Apodis is a double star, the two components of which are 103 arcseconds apart and visible through binoculars. Delta1 is a red giant star of spectral type M4III located 630 ± 30 light-years away. It is a semiregular variable that varies from magnitude +4.66 to +4.87, with pulsations of multiple periods