50 Aquarii
50 Aquarii, abbreviated 50 Aqr, is a single[7] star in the zodiac constellation of Aquarius. 50 Aquarii is its Flamsteed designation. It is a faint star with an apparent visual magnitude of 5.76[2] that is barely visible to the naked eye under good seeing conditions. The star is located near the ecliptic and thus is subject to lunar occultations.[8] Based upon an annual parallax shift of 12.2 mas[1] as seen from Earth orbit, it is located 266 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[2]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 22h 24m 27.06016s[1] |
Declination | −13° 31′ 45.7290″[1] |
Apparent magnitude (V) | 5.76[2] |
Characteristics | |
Spectral type | G7.5 III[3] |
B−V color index | 0.970±0.004[2] |
Astrometry | |
Radial velocity (Rv) | −21.1±2.9[2] km/s |
Proper motion (μ) | RA: +98.380[1] mas/yr Dec.: −2.909[1] mas/yr |
Parallax (π) | 12.2800 ± 0.0965[1] mas |
Distance | 266 ± 2 ly (81.4 ± 0.6 pc) |
Absolute magnitude (MV) | +0.03[2] |
Details[4] | |
Mass | 2.49±0.25 M☉ |
Radius | 14.17±0.81 R☉ |
Luminosity | 103.7±11.5 L☉ |
Surface gravity (log g) | 2.55±0.07 cgs |
Temperature | 4,897±34 K |
Metallicity [Fe/H] | −0.21±0.10 dex |
Rotational velocity (v sin i) | 4.07[5] km/s |
Age | 620±170 Myr |
Other designations | |
Database references | |
SIMBAD | data |
This is an evolved giant star with a stellar classification of G7.5 III[3] that is most likely (87% chance) on the red giant branch.[4] As such, it is estimated to be 620 million years old with 2.5 times the mass of the Sun and has expanded to 14 times the Sun's radius. The star is radiating 104 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,897 K.[4]
References
- 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.
- 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.
- Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- Reffert, Sabine; et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy & Astrophysics, 574: A116, arXiv:1412.4634, Bibcode:2015A&A...574A.116R, doi:10.1051/0004-6361/201322360. Note: the infobox values are based on the RGB model.
- Hekker, S.; Meléndez, J. (2007), "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters", Astronomy and Astrophysics, 475 (3): 1003, arXiv:0709.1145, Bibcode:2007A&A...475.1003H, doi:10.1051/0004-6361:20078233.
- "50 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 24, 2018.
- 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.
- Blow, G. L.; et al. (November 1982), "Photoelectric observations of lunar occultations. XIII", Astronomical Journal, 87: 1571–1584, Bibcode:1982AJ.....87.1571B, doi:10.1086/113247. See p. 1578, SAO 165044.