Astronomy:Gamma Apodis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[2] mas/yr Dec.: −78.212[2] mas/yr |
| Parallax (π) | 21.3033 ± 0.1523[2] mas |
| 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 | |
| Database references | |
| SIMBAD | data |
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]
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]
References
- ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 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, doi:10.1051/0004-6361/200911736, Bibcode: 2009A&A...508..833D.
- ↑ 4.0 4.1 Gontcharov, G. A. (2008), "Red giant clump in the Tycho-2 catalogue", Astronomy Letters 34 (11): 785, doi:10.1134/S1063773708110078, Bibcode: 2008AstL...34..785G.
- ↑ 5.0 5.1 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics 430: 303–311, doi:10.1051/0004-6361:20041440, Bibcode: 2005A&A...430..303C.
- ↑ 7.0 7.1 7.2 7.3 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode: 2015AJ....150...88L.
- ↑ 8.0 8.1 Stassun, Keivan G.; Oelkers, Ryan J.; Pepper, Joshua; Paegert, Martin; De Lee, Nathan; Torres, Guillermo; Latham, David W.; Charpinet, Stéphane et al. (2018), "The TESS Input Catalog and Candidate Target List", The Astronomical Journal 156 (3): 102, doi:10.3847/1538-3881/aad050, Bibcode: 2018AJ....156..102S.
- ↑ 9.0 9.1 9.2 9.3 9.4 Perdelwitz, V. et al. (March 2024), "Analysis of the public HARPS/ESO spectroscopic archive. Ca II H&K time series for the HARPS radial velocity database", Astronomy & Astrophysics 683: id. A125, doi:10.1051/0004-6361/202348263, Bibcode: 2024A&A...683A.125P.
- ↑ "gam Aps". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam+Aps.
- ↑ Makarov, Valeri V. (October 2003), "The 100 Brightest X-Ray Stars within 50 Parsecs of the Sun", The Astronomical Journal 126 (4): 1996–2008, doi:10.1086/378164, Bibcode: 2003AJ....126.1996M.
- ↑ (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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