Gamma Apodis

Gamma Apodis (γ Aps, γ Apodis) is the Bayer designation for a star in the southern circumpolar constellation of Apus. From parallax measurements, the distance to this star can be estimated as 150 ± 4 light-years (46.0 ± 1.2 pc).[4] It is visible to the naked eye with an apparent visual magnitude of 3.86.[2] A stellar classification of G9 III[2] identifies it as a giant star in the later stages of its evolution. It 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.[8]

Gamma Apodis
Location of γ Apodis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Apus
Right ascension 16h 33m 27.08379s[1]
Declination −78° 53′ 49.7372″[1]
Apparent magnitude (V) 3.86[2]
Characteristics
Spectral type G9 III[2]
U−B color index +0.62[3]
B−V color index +0.91[3]
Astrometry
Radial velocity (Rv)+5.7[2] km/s
Proper motion (μ) RA: –126.122 ± 0.688[4] mas/yr
Dec.: –78.699 ± 0.667[4] mas/yr
Parallax (π)21.7674 ± 0.5542[4] mas
Distance150 ± 4 ly
(46 ± 1 pc)
Absolute magnitude (MV)+0.41[5]
Details
Surface gravity (log g)3.5[6] cgs
Temperature5,040[6] K
Metallicity [Fe/H]–0.05[6] dex
Rotational velocity (v sin i)2.7[2] km/s
Other designations
FK5 611, GJ 626.1, HD 147675, HIP 81065, HR 6102, SAO 257407, CPD–78° 1103[7]
Database references
SIMBADdata

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).[9]

References
  1. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. da Silva, L.; et al. (December 2009), "Search for associations containing young stars (SACY). III. Ages and Li abundances", Astronomy and Astrophysics, 508 (2): 833–839, arXiv:0909.0677, Bibcode:2009A&A...508..833D, doi:10.1051/0004-6361/200911736.
  3. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
  4. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
  5. Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440.
  6. Abia, C.; et al. (November 1988), "Abundances of light metals and NI in a sample of disc stars", Astronomy and Astrophysics, 206 (1): 100–107, Bibcode:1988A&A...206..100A.
  7. "gam Aps". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-06-29.
  8. Makarov, Valeri V. (October 2003), "The 100 Brightest X-Ray Stars within 50 Parsecs of the Sun", The Astronomical Journal, 126 (4): 1996–2008, Bibcode:2003AJ....126.1996M, doi:10.1086/378164.
  9. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日
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