Epsilon Carinae

ε Carinae
Location of ε Carinae (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 08h 22m 30.83526s[1]
Declination −59° 30′ 34.1431″[1]
Apparent magnitude (V) 1.86[2] (2.166/4.121)[3]
Characteristics
Spectral type K3 III[4] + B2 Vp[5]
U−B color index +0.19[2]
B−V color index +1.27[2]
Variable type Eclipsing (suspected)[6]
Astrometry
Radial velocity (Rv)+11.6[7] km/s
Proper motion (μ) RA: –25.52[1] mas/yr
Dec.: 22.72[1] mas/yr
Parallax (π)5.39 ± 0.42 mas[1]
Distance610 ± 50 ly
(190 ± 10 pc)
Absolute magnitude (MV)−4.47[8] (−4.3, −1.8, −1.7)[9]
Details
ε Car A
Mass10.5[9] M
Radius151 ± 14[10][a] R
Luminosity8,128[10] L
Temperature4,460±90[10] K
Age31.2 ± 10.1[11] Myr
ε Car B
Mass7.30[9] M
Temperature20,417[9] K
Age20[9] Myr
Other designations
Avior, CD−59°1032, FK5 315, HIP 41037, HR 3307, SAO 235932
A: HD 71129
B: HD 71130
Database references
SIMBADε Carinae
A
B

Epsilon Carinae (ε Carinae, abbreviated Epsilon Car, ε Car), officially named Avior /ˈvjər/,[12] is a binary star in the southern constellation of Carina. At apparent magnitude +1.86 it is one of the brightest stars in the night sky, but is not visible from most of the northern hemisphere. The False Cross is an asterism formed of Delta Velorum, Kappa Velorum, Iota Carinae and ε Carinae. It is so called because it is sometimes mistaken for the Southern Cross, causing errors in astronavigation.[13]

Celestia simulation of the ε Carinae system

Epsilon Carinae is located roughly 560–660 light-years (170–200 parsecs) from the Sun.[1] Measurements during the Hipparcos mission give the pair an angular separation of 0.46 arcseconds with a difference in magnitude of 2.0.[5] At their estimated distance, this angle is equivalent to a physical separation of around 4 astronomical units.[14]

The primary component has an apparent visual magnitude of 2.2,[3] which by itself would still make it the third-brightest star in the constellation. It is an evolved giant star with a stellar classification of K0 III. However, examination of the ultraviolet flux from this star suggests it may instead be of spectral type K7.[5] The fainter secondary companion has an apparent visual magnitude of 4.1,[3] which, if it were a solitary star, would be bright enough to be seen with the naked eye. This is a hot, core hydrogen-fusing B-type main sequence star of spectral class B2 Vp.[5] The secondary may itself have an orbiting stellar companion of spectral class F8.[9] This pair may form an eclipsing binary system[14] with a period of 785 days (2.15 years), resulting in a magnitude change of 0.12 during each eclipse.[6][15]

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  2. ^ a b c Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
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  8. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  9. ^ a b c d e f Cite error: The named reference aj127_5_2915 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference lithium was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference mnras410_1_190 was invoked but never defined (see the help page).
  12. ^ "IAU Catalog of Star Names". Retrieved 28 July 2016.
  13. ^ Moore, Patrick (2010). Patrick Moore's Astronomy: Teach Yourself. Hachette. ISBN 978-1444129779.
  14. ^ a b Cite error: The named reference kaler was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference jaavso24_2_105 was invoked but never defined (see the help page).


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