Gamma Apodis
Star in the constellation Apus
From Wikipedia, the free encyclopedia
Gamma Apodis is a star in the southern circumpolar constellation of Apus. Its identifier is a Bayer designation that is Latinized from γ Apodis, and is abbreviated Gam Aps or γ Aps, respectively. It is visible to the naked eye with an apparent visual magnitude of 3.86.[3] From parallax measurements, the distance to this star can be estimated as 153 light-years (47 pc). The star is receding with a heliocentric radial velocity of +5.7 km/s.[3]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Apus[1] |
| Right ascension | 16h 33m 27.08252s[2] |
| Declination | −78° 53′ 49.7334″[2] |
| Apparent magnitude (V) | 3.86[3] |
| Characteristics | |
| Evolutionary stage | red clump[4] |
| Spectral type | G9 III[3] |
| U−B color index | +0.62[5] |
| B−V color index | +0.91[5] |
| Astrometry | |
| Radial velocity (Rv) | +5.7[3] km/s |
| Proper motion (μ) | RA: −125.575 mas/yr[2] Dec.: −78.212 mas/yr[2] |
| Parallax (π) | 21.3033±0.1523 mas[2] |
| Distance | 153 ± 1 ly (46.9 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.41[6] |
| Details | |
| Mass | 2.32[7] M☉ |
| Radius | 10.293[8] R☉ |
| Surface gravity (log g) | 3.074±0.081[9] cgs |
| Temperature | 5,151±50[9] K |
| Metallicity [Fe/H] | 0.090±0.042[9] dex |
| Rotational velocity (v sin i) | 5.016±0.417[9] km/s |
| Age | 2.67[7] Gyr |
| Other designations | |
| γ Aps, γ Apodis, CPD−78°1103, FK5 611, GJ 626.1, GJ 9563, HD 147675, HIP 81065, HR 6102, SAO 257407[10] | |
| Database references | |
| SIMBAD | data |
A stellar classification of G9 III[3] identifies Gamma Apodis as a giant star in the later stages of its evolution. This is a red clump giant, which means it is on the horizontal branch and is generating energy through core helium fusion.[4] The star has 2.3[7] times the mass of the Sun and has expanded to 10.3[8] times the Sun's radius. It is 2.7[7] billion years old and is spinning with a projected rotational velocity of 5 km/s.[9] This is an active X-ray source with a luminosity of 1.607×1030 erg s−1, making it one of the 100 strongest stellar X-ray sources within 50 parsecs of the Sun.[11]
Naming
In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 異雀 (Yì Què), meaning Exotic Bird, refers to an asterism consisting of γ Apodis, ζ Apodis, ι Apodis, β Apodis, δ Octantis, δ1 Apodis, η Apodis, α Apodis and ε Apodis. Consequently, γ Apodis itself is known as 異雀四 (Yì Què sì, English: the Fourth Star of Exotic Bird).[12]