Tau1 Aquarii, Latinized from τ1 Aquarii, is the Bayer designation for a single[11] star in the equatorial constellation of Aquarius. With an apparent visual magnitude of 5.66,[2] it is a faint naked eye that requires dark suburban skies for viewing. Parallax measurements made during the Hipparcos mission yield a distance estimate of roughly 355 light-years (109 parsecs) from Earth.[1] The star is drifting further away with a radial velocity of +15 km/s.[5] It is a candidate member of the Pisces-Eridanus stellar stream.[12]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 47m 42.76996s[1] |
| Declination | –14° 03′ 23.1419″[1] |
| Apparent magnitude (V) | +5.66[2] |
| Characteristics | |
| Spectral type | B9 V[3] |
| U−B color index | –0.25[4] |
| B−V color index | –0.05[4] |
| Astrometry | |
| Radial velocity (Rv) | +15[5] km/s |
| Proper motion (μ) | RA: +29.960[1] mas/yr Dec.: –9.009[1] mas/yr |
| Parallax (π) | 9.1849 ± 0.1301 mas[1] |
| Distance | 355 ± 5 ly (109 ± 2 pc) |
| Absolute magnitude (MV) | +0.74[6] |
| Details | |
| Mass | 2.68±0.05[7] M☉ |
| Radius | 2.0[8] R☉ |
| Luminosity | 63.5[7] L☉ |
| Temperature | 10,617[7] K |
| Rotational velocity (v sin i) | 185[7] km/s |
| Age | 100[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The stellar classification of τ1 Aquarii is B9 V;[3] right along the borderline between a B- and A-type main sequence star. This is a candidate silicon star; a type of Ap star of class CP2 that shows a magnetic field.[13] It is around 100[9] million years old and is spinning rapidly with a projected rotational velocity of 185 km/s.[7] The star has 2.7[7] times the mass of the Sun and double the Sun's radius.[8] It is radiating 63.5[7] times the luminosity of the Sun from its photosphere at an effective temperature of 10,617 K.[7] When examined in the infrared band, it displays an excess emission that is a characteristic of stars with an orbiting debris disk. The model that best fits the data suggests there are two concentric circumstellar disks.[9]
References
edit- ^ a b c d e f 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 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C.
- ^ a b 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.
- ^ a b Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ a b Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
- ^ 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 e f g h Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ a b c Morales, Farisa Y.; et al. (April 2011), "Common Warm Dust Temperatures Around Main-sequence Stars" (PDF), The Astrophysical Journal Letters, 730 (2): L29, Bibcode:2011ApJ...730L..29M, doi:10.1088/2041-8205/730/2/L29, S2CID 2360696.
- ^ "* tau01 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-03.
- ^ 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.
- ^ Curtis, Jason L.; et al. (August 2019), "TESS Reveals that the Nearby Pisces-Eridanus Stellar Stream is only 120 Myr Old", The Astronomical Journal, 158 (2): 11, arXiv:1905.10588, Bibcode:2019AJ....158...77C, doi:10.3847/1538-3881/ab2899, S2CID 166228270, 77.
- ^ Wraight, K. T.; et al. (2012), "A photometric study of chemically peculiar stars with the STEREO satellites - I. Magnetic chemically peculiar stars★", Monthly Notices of the Royal Astronomical Society, 420 (1): 757–772, arXiv:1110.6283, Bibcode:2012MNRAS.420..757W, doi:10.1111/j.1365-2966.2011.20090.x, S2CID 14811051.