VZ Camelopardalis

VZ Camelopardalis is a single,[7] variable star in the northern circumpolar constellation of Camelopardalis. It has a reddish hue and is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around 4.92.[2] The star is located at a distance of approximately 500 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +12 km/s.[2] It was considered a member of the Hyades Supercluster,[8] but in 1990 this was brought into question.[9]

VZ Camelopardalis
Observation data
Epoch J2000      Equinox J2000
Constellation Camelopardalis
Right ascension 07h 31m 04.48017s[1]
Declination +82° 24′ 41.2905″[1]
Apparent magnitude (V) 4.92[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type M4IIIa[4]
B−V color index +1.633±0.018[2]
Variable type Lb?[5]
Astrometry
Radial velocity (Rv)+11.90±0.22[2] km/s
Proper motion (μ) RA: −5.249[1] mas/yr
Dec.: −42.174[1] mas/yr
Parallax (π)6.4908 ± 0.2204[1] mas
Distance500 ± 20 ly
(154 ± 5 pc)
Absolute magnitude (MV)−1.00[2]
Details
Radius88.93+7.92
−15.25[1] R☉
Luminosity1252±48[1] L☉
Temperature3,641+359
−152[1] K
Other designations
VZ Cam, BD+82°201, FK5 3951, GC 9851, HD 55966, HIP 36547, HR 2742, SAO 1179[6]
Database references
SIMBADdata

This object is an aging red giant star on the asymptotic giant branch[3] with a stellar classification of M4IIIa.[4] Its variable nature was discovered by American astronomer J. Ashbrook in 1948.[10] This is a suspected slow irregular variable of sub-type Lb that varies in visual magnitude from 4.80 down to 4.96.[5] Long-term photometry measurements suggest there are at least four pulsation periods ranging from 27.1 to 39.0 days.[11] With the supply of hydrogen at its core exhausted the star has cooled and expanded until it has now reached 89 times the radius of the Sun. It is radiating 1,252 times the luminosity of the Sun from its photosphere at an effective temperature of 3,641 K.[1]

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data 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 source at VizieR.
  2. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal, 104 (1): 275–313, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
  4. Yamashita, Y. (1967), "MK Spectral Types of Bright M-Type Stars", Publications of the Dominion Astrophysical Observatory, 13: 47, Bibcode:1967PDAO...13...47Y.
  5. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  6. "VZ Cam". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-26.
  7. 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, S2CID 14878976.
  8. Eggen, O. J. (February 1985), "A systematic search for members of the Hyades supercluster. V. The red giants", Astronomical Journal, 90: 333–340, Bibcode:1985AJ.....90..333E, doi:10.1086/113736.
  9. Yamakawa, Fusatoshi; Uji-Iye, Kei-Ichi (August 1990), "A Candidate Star for Irregular Variability", Publications of the Astronomical Society of Japan, 42: L65–L67, Bibcode:1990PASJ...42L..65Y.
  10. Eggen, Olin J.; Iben, Icko, Jr. (April 1991), "First Giant Branch and Asymptotic Giant Branch Stars in Nearby Aggregates", Astronomical Journal, 101: 1377, Bibcode:1991AJ....101.1377E, doi:10.1086/115773.
  11. Tabur, V.; et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants", Monthly Notices of the Royal Astronomical Society, 400 (4): 1945–1961, arXiv:0908.3228, Bibcode:2009MNRAS.400.1945T, doi:10.1111/j.1365-2966.2009.15588.x, S2CID 15358380.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.