15 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 18m 11.07309s[1] |
| Declination | −04° 31′ 10.1276″[1] |
| Apparent magnitude (V) | 5.83[2] |
| Characteristics | |
| Spectral type | B7 III[3] or B5 V[4] |
| B−V color index | −0.130±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | −9.0±1.0[5] km/s |
| Proper motion (μ) | RA: +12.11[6] mas/yr Dec.: +12.94[6] mas/yr |
| Parallax (π) | 4.5632 ± 0.1345 mas[1] |
| Distance | 710 ± 20 ly (219 ± 6 pc) |
| Absolute magnitude (MV) | −1.62[2] |
| Details | |
| Mass | 5.7±0.2[7] M☉ |
| Radius | 3.4[8] R☉ |
| Luminosity | 821.67[2] L☉ |
| Surface gravity (log g) | 3.84[9] cgs |
| Temperature | 14,318[9] K |
| Rotational velocity (v sin i) | 20[10] km/s |
| Age | 65.2±25.1[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
15 Aquarii, abbreviated 15 Aqr, is a single,[12] blue-white star in the zodiac constellation of Aquarius. 15 Aquarii is the Flamsteed designation. It is a dim star that is just visible to the naked eye under good viewing conditions, having an apparent visual magnitude of 5.83.[2] Based upon an annual parallax shift of 4.6 mas,[1] it is located around 710 light years away. At that distance, the visual magnitude is diminished by an extinction of 0.18 due to interstellar dust.[13] It is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.[5] Relative to its neighbors, 15 Aqr has a peculiar velocity of 28.7+2.9
−3.1 km/s and may (62% chance) be a runaway star.[7]
Hube (1970) found a stellar classification of B7 III[3] for this star, which would suggest it is a B-type giant star. However, the Bright Star Catalogue (1964) listed it as a B-type main-sequence star with a class of B5 V,[4] and multiple sources use this instead.[7][10][8][9] The star is roughly 65[7] million years old with a projected rotational velocity of 20 km/s.[10] It has an estimated 5.7[7] times the mass of the Sun and about 3.4[8] times the Sun's radius. 15 Aquarii is radiating 822[2] times the Sun's luminosity from its photosphere at an effective temperature of 14,318 K.[9]
References[edit]
- ^ 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.
- ^ a b c d e f 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 Hube, Douglas P. (1970), "The radial velocities of 335 late B-type stars", Memoirs of the Royal Astronomical Society, 72: 233, Bibcode:1970MmRAS..72..233H.
- ^ a b Hoffleit, Dorrit (1964), Catalogue of Bright Stars (3rd revised ed.), New Haven, Conn.: Yale University Observatory, Bibcode:1964cbs..book.....H.
- ^ a b Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b van Leeuwen, F. (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 e f Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b c Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ a b c d Takeda, Yoichi; et al. (October 2010), "Oxygen and Neon Abundances of B-Type Stars in Comparison with the Sun", Publications of the Astronomical Society of Japan, 62 (5): 1239–1248, arXiv:1008.1220, Bibcode:2010PASJ...62.1239T, doi:10.1093/pasj/62.5.1239.
- ^ a b c Strom, Stephen E.; et al. (2005), "B Star Rotational Velocities in h and χ Persei: A Probe of Initial Conditions during the Star Formation Epoch?", The Astronomical Journal, 129 (2): 809–828, arXiv:astro-ph/0410337, Bibcode:2005AJ....129..809S, doi:10.1086/426748, S2CID 15059129.
- ^ "15 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 22, 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, S2CID 14878976.
- ^ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
