Tau2Aquarii
  | |
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h49m35.50157s[1] |
| Declination | –13° 35′ 33.4767″[1] |
| Apparent magnitude(V) | +4.042[2](3.98 to 4.04)[3] |
| Characteristics | |
| Spectral type | K5 III[4]or M0 III[5] |
| U−Bcolor index | +1.948[2] |
| B−Vcolor index | +1.566[2] |
| Variable type | Suspected[3] |
| Astrometry | |
| Radial velocity(Rv) | +1.0[6]km/s |
| Proper motion(μ) | RA:–13.71[1]mas/yr Dec.:–39.03[1]mas/yr |
| Parallax(π) | 10.27 ± 0.29mas[1] |
| Distance | 318 ± 9ly (97 ± 3pc) |
| Absolute magnitude(MV) | −1.28[7] |
| Details | |
| Radius | 51.5+4.6 −5.5[8]R☉ |
| Luminosity | 614±27[8]L☉ |
| Surface gravity(logg) | 1.63[9]cgs |
| Temperature | 4,007+232 −166[8]K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Tau2Aquarii,Latinizedfrom τ2Aquarii, is theBayer designationfor a single[11]starin theequatorialconstellationofAquarius.It is visible to the naked eye with anapparent visual magnitudeof +4.0.[2]Because the star lies near theeclipticit is subject tooccultationsby theMoon.[12]The star is located at a distance of approximately 318light yearsfrom theSunbased onparallax.[1]
This is an orange-hued[13]red giantstar with astellar classificationof K5 III.[4]After exhausting the supply of hydrogen at its core, the aging star cooled and expanded off themain sequence.It now has 52 times the radius of the Sun and is radiating 614 times the Sun's luminosity from its enlargedphotosphereat aneffective temperatureof 4,007 K.[8]This is a suspectedvariable starwith a brightness that has been measured ranging from visual magnitude 3.98 down to 4.04.[3]
A magnitude 9.94visual companionto this star was reported byW. Herschelin 1782, and it has the modern discovery code'H 6 97'.As of 2010, it was located at a wideangular separationof132.40″from the brighter star along aposition angleof 297°.[14]
References[edit]
- ^abcdefvan 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,S2CID18759600.
- ^abcdGutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards",Publ. Dept. Astron. Univ. Chile,1,Publicaciones Universidad de Chile, Department de Astronomy: 1–17,Bibcode:1966PDAUC...1....1G.
- ^abcSamus', N. N.; et al. (2017), "General catalogue of variable stars",Astronomy Reports,5.1,61(1): 80,Bibcode:2017ARep...61...80S,doi:10.1134/S1063772917010085,S2CID125853869
- ^abHouk, 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.
- ^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.
- ^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.
- ^Pace, G.; et al. (2003). "The Wilson-Bappu effect: A tool to determine stellar distances".Astronomy and Astrophysics.401(3): 997–1008.arXiv:astro-ph/0301637.Bibcode:2003A&A...401..997P.doi:10.1051/0004-6361:20030163.S2CID17029463.
- ^abcdBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData 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 sourceatVizieR.
- ^Bordé, P.; et al. (October 2002), "A catalogue of calibrator stars for long baseline stellar interferometry",Astronomy and Astrophysics,393:183–193,Bibcode:2002A&A...393..183B,doi:10.1051/0004-6361:20021020.
- ^"tau Aqr".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2021-06-08.
{{cite web}}:CS1 maint: postscript (link) - ^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.S2CID14878976.
- ^White, Nathaniel M.; Feierman, Barry H. (September 1987), "A Catalog of Stellar Angular Diameters Measured by Lunar Occultation",Astronomical Journal,94:751,Bibcode:1987AJ.....94..751W,doi:10.1086/114513.
- ^"The Colour of Stars",Australia Telescope, Outreach and Education,Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived fromthe originalon 2013-12-03,retrieved2012-01-16.
- ^Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog",The Astronomical Journal,122(6): 3466–3471,Bibcode:2001AJ....122.3466M,doi:10.1086/323920.
