44 Aquarii

44 Aquarii is a single^[10] star located 336^[1] light years away from the Sun in the equatorial constellation of Aquarius. 44 Aquarii is its Flamsteed designation.^[9] It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.75.^[2] This body is moving away from the Earth with a heliocentric radial velocity of +7.4 km/s.^[5]

44 Aquarii

Observation data Epoch J2000      Equinox J2000
Constellation	Aquarius
Right ascension	22h 17m 06.49946s[1]
Declination	–05° 23′ 13.8000″[1]
Apparent magnitude (V)	5.75[2]
Characteristics
Spectral type	G6 III[3]
U−B color index	+0.51[2]
B−V color index	+0.88[2]
Variable type	suspected[4]
Astrometry
Radial velocity (Rv)	+7.4[5] km/s
Proper motion (μ)	RA: –6.05[6] mas/yr Dec.: +18.67[6] mas/yr
Parallax (π)	9.7114 ± 0.0934 mas[1]
Distance	336 ± 3 ly (103.0 ± 1.0 pc)
Absolute magnitude (MV)	+0.51[3]
Details
Mass	2.53[3] M☉
Radius	9.14+0.38 −0.34[1] R☉
Luminosity	53.169±0.628[1] L☉
Surface gravity (log g)	2.70[7] cgs
Temperature	5,025[7] K
Metallicity [Fe/H]	–0.31[7] dex
Rotational velocity (v sin i)	1.8±0.8[8] km/s
Age	537[3] Myr
Other designations
44 Aqr, NSV 14100, BD−06°5960, FK5 3782, HD 211434, HIP 110023, HR 8504, SAO 145993[9]
Database references
SIMBAD	data

A stellar classification of G6 III^[3] indicates this is an evolved giant star, most likely (98% chance) on the horizontal branch,^[11] having exhausted the hydrogen at its core and expanded. It is a suspected variable star of unknown type.^[4] 44 Aquarii is 537^[3] million years old with about 2.53^[3] times the mass of the Sun and 9^[1] times the Sun's radius. The star is radiating 62^[3] times the Sun's luminosity from its photosphere at an effective temperature of 5,025 K.^[7] At this heat, the star has the golden-hued glow of a G-type star.

References

1. 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.
2. 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.
3. Takeda, Yoichi; Sato, Bun'ei; Murata, Daisuke (August 2008), "Stellar Parameters and Elemental Abundances of Late-G Giants", Publications of the Astronomical Society of Japan, 60 (4): 781–802, arXiv:0805.2434, Bibcode:2008PASJ...60..781T, doi:10.1093/pasj/60.4.781, S2CID 16258166.
4. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
5. Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W.
6. 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.
7. Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
8. Gray, David F. (1989), "The rotational break for G giants", Astrophysical Journal, 347: 1021–1029, Bibcode:1989ApJ...347.1021G, doi:10.1086/168192.
9. "* 44 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-16.
10. 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.
11. Stock, Stephan; et al. (August 2018), "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search", Astronomy & Astrophysics, 616: 15, arXiv:1805.04094, Bibcode:2018A&A...616A..33S, doi:10.1051/0004-6361/201833111, S2CID 119361866, A33.

External links

• Image 44 Aquarii