68 Aquarii

68 Aquarii
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Aquarius
Right ascension	22h 47m 33.12362s
Declination	−19° 36′ 48.1619″
Apparent magnitude (V)	5.24
Characteristics
Spectral type	G8III
B−V color index	+0.941±0.002
Astrometry
Radial velocity (Rv)	+24.54±0.27 km/s
Proper motion (μ)	RA: −103.390 mas/yr ; Dec.: −205.545 mas/yr
Parallax (π)	12.0902 ± 0.1605 mas
Distance	270 ± 4 ly ; (83 ± 1 pc)
Absolute magnitude (MV)	0.78
Details
Mass	1.39 M☉
Radius	10.05+0.35; −1.62 R☉
Luminosity	58.5±0.9 L☉
Surface gravity (log g)	2.8 cgs
Temperature	5,036+461; −85 K
Metallicity [Fe/H]	−0.43±0.02 dex
Rotational velocity (v sin i)	0.0 km/s
Age	3.79 Gyr
Other designations
	68 Aqr, BD−20°6486, HD 215721, HIP 112529, HR 8670, SAO 165293, LTT 9194
Database references
SIMBAD	data

68 Aquarii is a single^[6] star located 270 light years away from the Sun in the zodiac constellation of Aquarius. 68 Aquarii is its Flamsteed designation, though it also bears the Bayer designation of g² Aquarii.^[7] It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.24.^[2] The object is moving further from the Earth with a heliocentric radial velocity of +24.5 km/s.^[2]

This star is 3.79^[3] billion years old with a stellar classification of G8 III,^[8] indicating the star is a giant star that has exhausted the hydrogen at its core and expanded off the main sequence. It is a red clump giant,^[9] which means it is on the horizontal branch and is generating energy through helium fusion at its core. It has 1.39^[3] times the mass of the Sun and 10 times the Sun's radius. The star is radiating 59 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 5,036 K.^[1]

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ 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. Gaia DR2 record for this source at VizieR.
^ ^a ^b ^c ^d ^e ^f ^g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
^ ^a ^b ^c ^d Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
^ ^a ^b Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
^ "68 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-05-18.
^ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ Kostjuk, N. D. (2002), "HD 215721", HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index, Institute of Astronomy of Russian Academy of Sciences, retrieved 2019-05-19; CDS ID IV/27A.
^ Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
^ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121

[GaiaDR2-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ 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. Gaia DR2 record for this source at VizieR.

[Anderson2012-2] ^ ^a ^b ^c ^d ^e ^f ^g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.

[luck2015-3] Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.

[Massarotti2008-4] Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.

[SIMBAD-5] "68 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-05-18.

[Eggleton2008-6] Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.

[Kostjuk2002-7] Kostjuk, N. D. (2002), "HD 215721", HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index, Institute of Astronomy of Russian Academy of Sciences, retrieved 2019-05-19; CDS ID IV/27A.

[houk1978-8] Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.

[Alves2000-9] Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121

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68 Aquarii

References

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