|Pronunciation||//, genitive //|
|Right ascension||13h 51m 07.5441s–18h 27m 27.8395s|
|Area||206 sq. deg. (67th)|
|Stars with planets||2|
|Stars brighter than 3.00m||0|
|Stars within 10.00 pc (32.62 ly)||0|
|Brightest star||α Aps (3.83m)|
|Nearest star||HD 128400
(66.36 ly, 20.35 pc)
|Visible at latitudes between +5° and −90°.
Best visible at 21:00 (9 p.m.) during the month of July.
Apus is a small constellation in the southern sky, first defined in the late 16th century. Its name means "no feet" in Greek, and it represents a bird-of-paradise, which was once wrongly believed to lack feet. Its genitive is "Apodis". The orange giant Alpha Apodis is the brightest star in the constellation. Two star systems have been found to have planets.
Apus was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman who had sailed on the first Dutch trading expedition, known as the Eerste Schipvaart, to the East Indies. It first appeared on a 35-cm (14 in) diameter celestial globe published in 1598 in Amsterdam by Plancius with Jodocus Hondius. De Houtman included it in his southern star catalogue in 1603 under the Dutch name De Paradijs Voghel, "The Bird of Paradise", and Plancius called the constellation Paradysvogel Apis Indica; the first word is Dutch for "bird of paradise". Apis (Latin for "bee") is presumably a typographical error for avis ("bird"). Bayer called it Apis Indica while Johannes Kepler and his son in law Jacob Baertsch called it Apus or Avis Indica. The name Apus is derived from the Greek apous, meaning "without feet". This referred to the Western misconception that the bird-of-paradise had no feet, which arose because the only specimens available in the West had their feet and wings removed. Such specimens began to arrive in Europe in 1522, when the survivors of Ferdinand Magellan's expedition brought them home.
After its introduction on Plancius's globe, the constellation's first known appearance in a celestial atlas was in German cartographer Johann Bayer's Uranometria of 1603, where it was called "Apis Indica".
Richard Allen reports Semler's assertion that de Houtman, who observed the southern constellations from the island of Sumatra, took his ideas for the formation of Apus (as well as Phoenix and Indus) from the Chinese, who knew the stars of Apus as the "Little Wonder Bird", and that Semler's assertion was disputed by Ideler (though Ideler acknowledged the Chinese constellations).
Covering 206.3 square degrees and hence 0.500% 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.[a] 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 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 13h 49.5m and 18h 27.3m, while the declination coordinates are between -67.48° and -83.12°.
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.[b] Beta, Gamma and Delta Apodis form a narrow triangle, with Alpha Apodis lying to the east.
Alpha Apodis is an orange giant of spectral type K3III 447 ± 8 light years away from Earth, with a 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, now shining with a luminosity approximately 928 times that of the Sun, with a surface temperature of 4312 K. Beta Apodis is an orange giant 157 ± 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 an yellow giant of spectral type G8III located 156 ± 1 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 760 ± 30 light years away. It is a semiregular variable that varies from magnitude +4.66 to +4.87, with pulsations of multiple periods of 68.0, 94.9 and 101.7 days. Delta2 is an orange giant star located 610 ± 30 light years away, with a magnitude of 5.3. The separate components can be resolved with binoculars, a telescope, or the naked eye.
Zeta Apodis is a star that has swollen and cooled to become an orange giant of spectral type K1III, with a surface temperature of 4649 K and a luminosity 133 times that of the Sun. It is 297 ± 8 light-years distant.
Eta Apodis is a white main sequence star located 138 ± 1 light-years distant. Of apparent magnitude 4.89, it is in reality 1.77 times as massive, 15.5 times as luminous as the Sun and has 2.13 times its radius. Aged 250 ± 200 milion years old, this star is emitting an excess of 24 μm infrared radiation, which may be caused by a debris disk of dust orbiting at a distance of more than 31 astronomical units from it.
Theta Apodis is a cool red giant of spectral type M7 III located 370 ± 20 light years distant. It shines with a luminosity approximately 3879 times that of the Sun and has a surface temperature of 3151 K. A semiregular variable, it varies by 0.56 magnitudes with a period of 119 days—or approximately 4 months, It is losing mass at the rate of 1.1 × 10−7 times the mass of the Sun per year through its stellar wind. Dusty material ejected from this star is interacting with the surrounding interstellar medium, forming a bow shock as the star moves through the galaxy.
Iota Apodis is a binary star system around 1300 light-years distant, that is composed of two blue-white main sequence stars that orbit each other every 51.441 years. Of spectral types B9V and B9.5 V, they are each around three times as massive as the Sun.
NO Apodis is a red giant of spectral type M3III that varies between magnitudes 5.71 and 5.95. Located around 883 light-years distant, it shines with a luminosity approximately 2059 times that of the Sun and has a surface temperature of 3568 K. S Apodis is a rare R Coronae Borealis variable, an extremely hydrogen-deficient supergiant thought to have arisen as the result of the merger of two white dwarfs; fewer than 100 have been discovered as of 2012. It has a baseline magnitude of 9.7.
Two star systems have had exoplanets discovered by doppler spectroscopy, and the substellar companion of a third star system—the sunlike star HD 131664—has turned out to be a brown dwarf with a predicted mass of the companion to 23 times that of Jupiter (minimum of 18 and maximum of 49 Jovian masses). HD 134606 is a yellow sunlike star of spectral type G6IV that has begun expanding and cooling off the main sequence. Three planets orbit it with periods of 12, 59.5 and 459 days, successively larger as they are further away from the star. HD 137388 is another star—of spectral type K2IV—that is cooler than the Sun and has begun cooling off the main sequence. Around 47% as luminous and 88% as massive as the Sun, with 85% of its diameter, it is thought to be around 7.4 ± 3.9 billion years old. It has a planet that is 79 times as massive as the Earth and orbits its sun every 330 days at an average distance of 0.89 AU. 
The most prominent deep-sky objects in Apus include the globular clusters NGC 6101 and IC 4499 as well as the spiral galaxy IC 4633.
- NGC 6101 is a 14th magnitude globular cluster, located seven degrees north of Gamma Apodis.
- IC 4499 is a loose globular cluster in the medium-far galactic halo. Its apparent magnitude is 10.6, and it is unique because it is younger than most other globular clusters in the same region as determined by its metallicity.
- IC 4633 is a very faint spiral galaxy  surrounded by a vast amount of Milky Way line-of-sight Integrated Flux Nebulae.
When the Ming Dynasty Chinese astronomer Xu Guangqi adapted the European southern hemisphere constellations to the Chinese system in The Southern Asterisms, he combined Apus with some of the stars in Octans to form the "Exotic Bird" (異雀, Yìquè).
- While parts of the constellation technically rise above the horizon to observers between the 7°N and 22°N, stars within a few degrees of the horizon are to all intents and purposes unobservable.
- Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban-rural transition night skies.
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