Astronomy:Tau2 Serpentis

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Short description: Star in the constellation Serpens


τ2 Serpentis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Serpens[1]
Right ascension  15h 32m 09.67495s[2]
Declination +16° 03′ 22.2056″[2]
Apparent magnitude (V) 6.22[1]
Characteristics
Evolutionary stage main sequence[3]
Spectral type B9V[4]
U−B color index −0.23[5]
B−V color index −0.038±0.005[1]
Astrometry
Radial velocity (Rv)−19.3±2.7[1] km/s
Proper motion (μ) RA: −2.92[6] mas/yr
Dec.: +6.48[6] mas/yr
Parallax (π)6.7936 ± 0.0928[2] mas
Distance480 ± 7 ly
(147 ± 2 pc)
Absolute magnitude (MV)+0.44[1]
Details
Mass2.82[7] M☉
Radius2.70[7] R☉
Luminosity91[7] L☉
Surface gravity (log g)4.02[7] cgs
Temperature10,839[7] K
Rotational velocity (v sin i)154[3] km/s
Age278[8] Myr
Other designations
τ2 Ser, 12 Serpentis, BD+16°2797, GC 20880, HD 138527, HIP 76069, HR 5770, SAO 101600, PPM 131484[9]
Database references
SIMBADdata

Tau2 Serpentis, Latinized from τ2 Serpentis, is a star in the constellation of Serpens, located approximately 480 light-years from the Sun.[2] It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.22.[1] The star is drifting closer with a radial velocity of −19 km/s.[1]

This object is a late B-type main-sequence star with a stellar classification of B9V.[4] It is a probable Lambda Boötis star.[1][10] The star is 278[8] million years old and is spinning with a projected rotational velocity of 154 km/s.[3] It has nearly three times the mass and radius of the Sun. Tau2 Serpentis is radiating 91 times the Sun's luminosity from its photosphere at an effective temperature of 10,839 K.[7]

There is evidence of a possible companion, which is contributing about 15% to the total emission of the system.[11]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 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. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  3. ↑ 3.0 3.1 3.2 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, Bibcode: 2012A&A...537A.120Z. 
  4. ↑ 4.0 4.1 Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode: 1969AJ.....74..375C. 
  5. ↑ Hoffleit, D.; Warren, Jr., W. H., The Bright Star Catalogue (5th Revised ed.), CDS.  HR 5770. Accessed on line September 19, 2008.
  6. ↑ 6.0 6.1 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S. 
  8. ↑ 8.0 8.1 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G. 
  9. ↑ "tau02 Ser". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tau02+Ser. 
  10. ↑ Murphy, Simon J. et al. (October 2015), "An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue", Publications of the Astronomical Society of Australia 32: 43, doi:10.1017/pasa.2015.34, e036, Bibcode: 2015PASA...32...36M 
  11. ↑ Zverko, J. et al. (January 2013), "Stars with discrepant v sin i as derived from Ca II λ 3933 Å and Mg II λ 4481 Å lines. III. Stars with v sin i ( λ 3933 Å) < v sin i ( λ 4481 Å)", Astrophysical Bulletin 68 (1): 57–77, doi:10.1134/S1990341313010069, Bibcode: 2013AstBu..68...57Z.