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Upsilon Carinae

υ Carinae
Location of υ Carinae (circled)
Observation data
Epoch J2000      Equinox J2000
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 mas[2]
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. ^ a b 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. XHIP record for this object at VizieR.
  2. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
  3. ^ a b c d 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. ^ a b c 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
  5. ^ a b c d e f 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. ^ a b Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  7. ^ a b c d e f g 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, arXiv:1707.00560, Bibcode:2017MNRAS.471.1926N, doi:10.1093/mnras/stx1549, ISSN 0035-8711
  8. ^ "CCDM J09471-6504AB -- Double or multiple star", SIMBAD, Centre de Données astronomiques de Strasbourg, 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 Archived 2013-05-13 at the Wayback Machine
  11. ^ Precession
  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, Bibcode:1986MNRAS.223...79M, doi:10.1093/mnras/223.1.79
Prefix: a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9

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