Astronomy:Tau1 Aquarii

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Short description: Star in the constellation Aquarius


τ1 Aquarii
Aquarius IAU.svg
Red circle.svg
Location of τ1 Aquarii (circled)
Observation data
Equinox J2000.0]] (ICRS)
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[1] mas
Distance355 ± 5 ly
(109 ± 2 pc)
Absolute magnitude (MV)+0.74[6]
Details
Mass2.68±0.05[7] M
Radius2.0[8] R
Luminosity63.5[7] L
Temperature10,617[7] K
Rotational velocity (v sin i)185[7] km/s
Age100[9] Myr
Other designations
τ1 Aqr, 69 Aquarii, BD–14 6346, GC 31802, HD 215766, HIP 112542, HR 8673, SAO 165298, ADS 16268, WDS J22477-1403A[10]
Database references
SIMBADdata

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]

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

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 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, Bibcode1968MNSSA..27...11C. 
  3. 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  4. 4.0 4.1 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode1978A&AS...34....1N. 
  5. 5.0 5.1 Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Carnegie Institute Washington D.C. Publication (Carnegie Institution of Washington), Bibcode1953GCRV..C......0W. 
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode2012A&A...537A.120Z. 
  8. 8.0 8.1 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, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  9. 9.0 9.1 9.2 Morales, Farisa Y. et al. (April 2011), "Common Warm Dust Temperatures Around Main-sequence Stars", The Astrophysical Journal Letters 730 (2): L29, doi:10.1088/2041-8205/730/2/L29, Bibcode2011ApJ...730L..29M, https://authors.library.caltech.edu/24736/1/Morales2011p15446Astrophys_J_Lett.pdf. 
  10. "* tau01 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+tau01+Aqr. 
  11. 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  12. 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, doi:10.3847/1538-3881/ab2899, 77, Bibcode2019AJ....158...77C. 
  13. 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, doi:10.1111/j.1365-2966.2011.20090.x, Bibcode2012MNRAS.420..757W. 

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