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Alpha Apodis - Wikipedia

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α Apodis
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Location of α Apodis (circled)
Constellation	Apus
Right ascension	14^h 47^m 51.71203^s^[1]
Declination	−79° 02′ 41.1032″^[1]
Apparent magnitude (V)	3.825^[2]
Characteristics
Spectral type	K2.5III^[2]
U−B color index	+1.68^[3]
B−V color index	+1.43^[3]
R−I color index	+0.53^[4]
Astrometry

Radial velocity (R_v)	−1.1^[5] km/s
Proper motion (μ)	RA: −7.395^[6] mas/yr Dec.: −15.726^[6] mas/yr
Parallax (π)	7.5519 ± 0.3237 mas^[6]
Distance	430 ± 20 ly (132 ± 6 pc)
Absolute magnitude (M_V)	−1.67^[7]

Details

Mass	4.46^[8] `M`_☉
Radius	65 ± 5^[9]^[a] `R`_☉
Luminosity	1,072±22^[9] `L`_☉
Temperature	4,090±80^[9] K
Metallicity [Fe/H]	-0.3^[9] dex

Other designations
α Aps, Alpha Apodis, Alpha Aps, CPD−78°893, FK5 542, HD 129078, HIP 72370, HR 5470, SAO 257193.^[2]
Database references
SIMBAD	data

Alpha Apodis (Alpha Aps, α Apodis, α Aps) is the brightest star in the southern circumpolar constellation of Apus, with an apparent magnitude of approximately 3.825.^[10] It had the Greek alpha designation as part of the constellation which Johann Bayer called Apis Indica in his 1603 Uranometria star atlas.^[11] With a declination of –79°, this is a circumpolar star for much of the southern hemisphere. It can be identified on the night sky by drawing an imaginary line through Alpha Centauri and Alpha Circini then extending it toward the south celestial pole.^[12]

This is a giant star with a stellar classification of K2.5III,^[2] indicating that this star has consumed the hydrogen at its core and has evolved away from the main sequence. It has expanded to an estimated radius of about 65 times the radius of the Sun and is emitting 1,000 times the Sun's luminosity. The photosphere has an effective temperature of 4,090 K,^[9] giving the star the characteristic orange hue of a K-type star.^[13] Based upon parallax measurements, this star is 430 ± 20 light-years from the Earth.^[6] It is not known to have a companion.^[14]

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 α Apodis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ Octantis, δ¹ Apodis, η Apodis, and ε Apodis. Consequently, α Apodis itself is known as 異雀八 (Yì Què bā, English: the Eighth Star of Exotic Bird.)^[15]

Notes

^ Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
${\sqrt {{\biggl (}{\frac {5,772}{4,090}}{\biggr )}^{4}\cdot 10^{3.03}}}=65.19\ R_{\odot }$ .

References

^ ^a ^b 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, S2CID 18759600.
^ ^a ^b ^c ^d "alf Aps -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-12-23.
^ ^a ^b 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.
^ HR 5470, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed online October 3, 2008.
^ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
^ ^a ^b ^c ^d 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.
^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430 (1): 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.
^ Kervella, Pierre; Arenou, Frédéric; Mignard, François; Thévenin, Frédéric (2019-03-01). "Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly". Astronomy and Astrophysics. 623: A72. arXiv:1811.08902. Bibcode:2019A&A...623A..72K. doi:10.1051/0004-6361/201834371. ISSN 0004-6361.
^ ^a ^b ^c ^d ^e Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (2020-01-01). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy and Astrophysics. 633: A34. arXiv:1910.12732. Bibcode:2020A&A...633A..34C. doi:10.1051/0004-6361/201936360. ISSN 0004-6361.
^ Kaler, James B., "Alpha Aps", Stars, University of Illinois, archived from the original on 2008-12-02, retrieved 2011-12-23.
^ Ridpath, Ian, "Apus, the bird of paradise", Ian Ridpath's Star Tales, retrieved 2011-12-25.
^ Moore, Patrick (2000), Exploring the night sky with binoculars (4th ed.), Cambridge University Press, p. 113, ISBN 0-521-79390-4.
^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on February 22, 2012, retrieved 2012-01-16.
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日 Archived 2011-05-22 at the Wayback Machine

Constellation of Apus

Stars

Bayer	α β γ δ ε ζ η θ ι κ¹ κ²
Variable	R (not variable) S Z MY NN NO
HR	5240 5279 5306 5327 5389 5520 5547 5555 5628 5757 5786 5955 6135 6357 6373 6635 6646 6731 6751
HD	128294 129899 131664 134606 137366 137388 (Karaka) 141846 152010
Other	Godzilla star

Star
clusters

NGC	6101
Other	IC 4499

Nebulae	Hen 2-131

Galaxies	Sunburst galaxy