Astronomy:Upsilon Carinae

From HandWiki
Short description: Binary star in the constellation Carina
Not to be confused with Y Carinae.
υ Carinae
Location of υ Carinae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Carina[1]
Right ascension  09h 47m 06.12170s[2]
Declination −65° 04′ 19.2267″[2]
Apparent magnitude (V) 2.97[3] (+3.08/+6.25[4])
Characteristics
Spectral type A8 Ib + B7 III[5]
U−B color index +0.13[3]
B−V color index +0.27[3]
Astrometry
Radial velocity (Rv)+13.6±0.5[6] km/s
Proper motion (μ) RA: −11.51[2] mas/yr
Dec.: +4.71[2] mas/yr
Parallax (π)2.27 ± 0.28[2] mas
Distanceapprox. 1,400 ly
(approx. 440 pc)
Absolute magnitude (MV)−5.26[1]
Details
υ Car A
Mass10.88[7] M☉
Radius96.6 – 100[7] R☉
Surface gravity (log g)1.4±0.1[7] cgs
Temperature7,500±100[7] K
Age23.4[7] Myr
υ Car B
Mass8[5] M☉
Surface gravity (log g)3.3±0.1[5] cgs
Temperature23,000±1,600[5] K
Other designations
υ Car, CPD−64°1084, GC 13506, HIP 48002, WDS J09471-6504[8]
A: HD 85124, HR 3890, SAO 250696
B: HD 85123, HR 3891, SAO 250695
Database references
SIMBADsystem
A
B

Upsilon Carinae is a double star in the southern constellation of Carina. Its name is a Bayer designation that is Latinized from υ Carinae, and abbreviated Upsilon Car or υ Car. This pair is part of the Diamond Cross asterism in southern Carina. The Upsilon Carinae system has a combined apparent magnitude of +2.97[3] and is approximately 1,400 light years (440 parsecs) from Earth.[2] It is drifting further away with a line of sight velocity of +14 km/s.[6]

In Chinese, 海石 (Hǎi Dàn), meaning Sea Rock, refers to an asterism consisting of υ Carinae, ε Carinae, ι Carinae, HD 83183 and HD 84810.[9] Consequently, υ Carinae itself is known as 海石五 (Hǎi Dàn wǔ, English: the Fifth Star of Sea Rock.)[10]

In the next 7500 years, the south Celestial pole will pass close to these stars and Iota Carinae (8100 CE).[11]

Properties

The primary component, υ Carinae A, has a stellar classification of A8 Ib, making it a supergiant star that has exhausted the hydrogen at its core and evolved away from its brief main sequence lifetime as an B-type star.[7] With an apparent magnitude of +3.08,[4] it has an effective temperature of about 7,500 K,[7] giving it a white hue. The companion, υ Carinae B, is a giant star with a classification of B7 III,[4] although Mandrini and Niemela (1986) suggested it may be a subgiant star with a classification of B4–5 IV.[5] The outer envelope of this star has an effective temperature of around 23,000 K, resulting in the blue-white hue of a B-type star.

The two stars have an angular separation of 5.030 arcseconds. As a binary star system, they would have an estimated orbital period of at least 19,500 years and a present-day separation of around 2,000 Astronomical Units.[5] This system is roughly 12 million years old.[12]

References

  1. ↑ 1.0 1.1 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 2.4 2.5 van Leeuwen, F. (November 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 
  3. ↑ 3.0 3.1 3.2 3.3 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series 34: 1–49, Bibcode: 1978A&AS...34....1N 
  4. ↑ 4.0 4.1 4.2 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, Bibcode: 2008MNRAS.389..869E 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Samedov, Z. A. (1988), "On the visual binary υ Car and the chemical composition of its brighter component", Izvestiya Krymskoj Astronomicheskoj Observatorii 79: 57–63, Bibcode: 1988IzKry..79...57S 
  6. ↑ 6.0 6.1 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Neiner, Coralie et al. (October 2017), "Discovery of magnetic A supergiants: the descendants of magnetic main-sequence B stars", Monthly Notices of the Royal Astronomical Society 471 (2): 1926–1935, doi:10.1093/mnras/stx1549, ISSN 0035-8711, Bibcode: 2017MNRAS.471.1926N 
  8. ↑ "CCDM J09471-6504AB -- Double or multiple star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Upsilon+Carinae, retrieved 2012-01-26 
  9. ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  10. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 28 日
  11. ↑ Precession, http://moonkmft.co.uk/Precession.html 
  12. ↑ Mandrini, C. H.; Niemela, V. S. (November 1986), "On the visual binary Upsilon Carinae", Monthly Notices of the Royal Astronomical Society 223: 79–85, doi:10.1093/mnras/223.1.79, Bibcode: 1986MNRAS.223...79M 



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Upsilon_Carinae&oldid=3916801"