30 Aquarii
30 Aquarii is a single[10] star located about 301 light years away from the Sun in the zodiac constellation of Aquarius. 30 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.56.[2] The star is moving further from the Earth with a heliocentric radial velocity of 40 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 03m 16.45803s[1] |
| Declination | −06° 31′ 20.6748″[1] |
| Apparent magnitude (V) | 5.558[2] |
| Characteristics | |
| Evolutionary stage | giant |
| Spectral type | K1 IV[3] or G8 III[4] |
| B−V color index | 0.951[2] |
| Variable type | Constant[5] |
| Astrometry | |
| Radial velocity (Rv) | 39.74[2] km/s |
| Proper motion (μ) | RA: +45.635[1] mas/yr Dec.: +8.681[1] mas/yr |
| Parallax (π) | 10.8432 ± 0.3325 mas[1] |
| Distance | 301 ± 9 ly (92 ± 3 pc) |
| Absolute magnitude (MV) | 0.88[6] |
| Details | |
| Mass | 2.01[2] M☉ |
| Radius | 9.86+0.23 −0.25[1] R☉ |
| Luminosity | 54.7±1.9[1] L☉ |
| Surface gravity (log g) | 2.860[7] cgs |
| Temperature | 4,944±79[2] K |
| Metallicity [Fe/H] | −0.11[7] dex |
| Rotational velocity (v sin i) | 1.6[8] km/s |
| Age | 1.98[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an aging G-type giant star[6][5] with a stellar classification of G8 III,[4] although Houk and Swift (1999) found a class of K1 IV.[3] It is a red clump giant,[6] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star is nearly two[2] billion years old with a leisurely rotation rate, showing a projected rotational velocity of 1.6 km/s.[8] It has double[2] the mass of the Sun and has expanded to ten[1] times the Sun's radius. The star is radiating 55[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,944 K.[2]
References edit
- ^ 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 h i j k 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 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ a b 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 Henry, Gregory W.; et al. (September 2000), "Photometric Variability in a Sample of 187 G and K Giants", The Astrophysical Journal Supplement Series, 130 (1): 201–225, Bibcode:2000ApJS..130..201H, CiteSeerX 10.1.1.40.8526, doi:10.1086/317346, S2CID 17160805.
- ^ a b c 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.
- ^ a b McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527.
- ^ 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, S2CID 121883397
- ^ "30 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-05-16.
- ^ 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.
External links edit
- . Star Date Pages. Alcyone Astronomical Software. Archived from the original on 2005-09-03. Retrieved 2008-06-22.