Astronomy:HD 89998

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Short description: Star in the constellation Vela
HD 89998
Observation data
Equinox J2000.0]] (ICRS)
Constellation Vela[1]
Right ascension  10h 22m 19.58477s[2]
Declination −41° 38′ 59.8592″[2]
Apparent magnitude (V) 4.82[1]
Characteristics
Spectral type K1 III[3]
B−V color index 1.095±0.055[1]
Astrometry
Radial velocity (Rv)+20.9±0.8[4] km/s
Proper motion (μ) RA: −27.664[2] mas/yr
Dec.: +60.090[2] mas/yr
Parallax (π)15.9154 ± 0.1375[2] mas
Distance205 ± 2 ly
(62.8 ± 0.5 pc)
Absolute magnitude (MV)0.84[1]
Details
Mass1.9[5] M
Radius11.0[6] R
Luminosity56[6] L
Surface gravity (log g)2.77[5] cgs
Temperature4,761[6] K
Metallicity [Fe/H]+0.12[5] dex
Rotational velocity (v sin i)<1.0[7] km/s
Other designations
r Vel, NSV 4837, CD−41°5809, FK5 1268, HD 89998, HIP 50799, HR 4080, SAO 221998[8]
Database references
SIMBADdata

HD 89998 (r Velorum) is a single[9] star in the southern constellation of Vela. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.82.[1] The distance to HD 89998, as determined from its annual parallax shift of 15.9 mas,[2] is 205 light years. The star is moving further from the Earth with a heliocentric radial velocity of +21 km/s,[4] having come within 140 ly some 1.552 million years ago.[1]

This is an evolved giant star with a stellar classification of K1 III.[3] The measured angular diameter of this star, after correcting for limb darkening, is 1.72±0.02 mas.[10] At the estimated distance of this star, this yields a physical size of 11.6 times the radius of the Sun.[11] It is radiating 56 times the Sun's luminosity from its enlarged photosphere at en effective temperature of 4,761 K.[6]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 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.
  3. 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  4. 4.0 4.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  5. 5.0 5.1 5.2 Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G. et al. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics 691: A98. doi:10.1051/0004-6361/202451427. Bibcode2024A&A...691A..98K. 
  6. 6.0 6.1 6.2 6.3 Hon, Marc; Huber, Daniel; Kuszlewicz, James S.; Stello, Dennis; Sharma, Sanjib; Tayar, Jamie; Zinn, Joel C.; Vrard, Mathieu et al. (2021). "A "Quick Look" at All-sky Galactic Archeology with TESS: 158,000 Oscillating Red Giants from the MIT Quick-look Pipeline". The Astrophysical Journal 919 (2): 131. doi:10.3847/1538-4357/ac14b1. Bibcode2021ApJ...919..131H. 
  7. De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars. V. Southern stars". Astronomy and Astrophysics 561: A126. doi:10.1051/0004-6361/201220762. Bibcode2014A&A...561A.126D. 
  8. "HD 85622". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+85622. 
  9. Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  10. Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode2005A&A...431..773R. 
  11. Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41.  The radius (R*) is given by:
    2R*=(10362.81.72) AU0.0046491 AU/R23.2R