Astronomy:BE Camelopardalis

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Short description: Variable star in the Camelopardalis constellation
BE Camelopardalis
BECamLightCurve.png
A light curve for BE Camelopardalis, plotted from Hipparcos data[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Camelopardalis
Right ascension  03h 49m 31.27742s[2]
Declination +65° 31′ 33.5567″[2]
Apparent magnitude (V) 4.39[3] (4.35 - 4.48)[4]
Characteristics
Evolutionary stage asymptotic giant branch[5]
Spectral type M2 II[6]
B−V color index 1.870±0.029[3]
Variable type Lc[4]
Astrometry
Radial velocity (Rv)−1.70±1.47[3] km/s
Proper motion (μ) RA: +0.304[2] mas/yr
Dec.: −17.482[2] mas/yr
Parallax (π)4.10 ± 0.46[2] mas
Distanceapprox. 800 ly
(approx. 240 pc)
Absolute magnitude (MV)−2.51[3]
Details
Mass2.93[7] M
Radius176[8] R
Luminosity4,613 - 4,786[8] L
Temperature3,615±170[8] K
Other designations
BE Cam, BD+65°369, HD 23475, HIP 17884, HR 1155, SAO 12916[9]
Database references
SIMBADdata

BE Camelopardalis is a solitary[10] variable star in the northern circumpolar constellation of Camelopardalis. It is visible to the naked eye as a faint, red-hued point of light with an apparent visual magnitude that fluctuates around 4.39.[3] The star is located roughly 800 light years away from the Sun based on stellar parallax.[2]

This object is an M-type bright giant with a stellar classification of M2 II,[6] and is currently on the asymptotic giant branch. It is classified as an irregular variable of subtype Lc and its brightness varies from magnitude +4.35 down to +4.48.[4] Having exhausted the supply of hydrogen at its core, the star has expanded to around 176[8] times the Sun's radius. It has 2.9[7] times the Sun's mass and is radiating over four thousand times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,615 K.[8]

References

  1. "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access. 
  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 3.2 3.3 3.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  4. 4.0 4.1 4.2 Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode2017ARep...61...80S. 
  5. Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal 104 (1): 275–313. doi:10.1086/116239. Bibcode1992AJ....104..275E. 
  6. 6.0 6.1 "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal 628 (2): 973–985. August 2005. doi:10.1086/430901. Bibcode2005ApJ...628..973L. 
  7. 7.0 7.1 Hohle, M. M. et al. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten 331 (4): 349. doi:10.1002/asna.200911355. Bibcode2010AN....331..349H. 
  8. 8.0 8.1 8.2 8.3 8.4 Messineo, M.; Brown, A. G. A. (2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal 158 (1): 20. doi:10.3847/1538-3881/ab1cbd. Bibcode2019AJ....158...20M. 
  9. "BE Cam". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=BE+Cam. 
  10. 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.