V345 Carinae

This article is about E Carinae. For e Carinae, see HD 73390 and HD 73389.
V345 Carinae

A light curve for V345 Carinae, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 09h 05m 38.37267s[2]
Declination −70° 32′ 18.5832″[2]
Apparent magnitude (V) +4.66[3] (4.67 to 4.78)[4]
Characteristics
Spectral type B2(IV)n[5]
B−V color index −0.149±0.011[3]
Variable type Be[6]
Astrometry
Radial velocity (Rv)+19.0±7.4[3] km/s
Proper motion (μ) RA: −3.017[2] mas/yr
Dec.: +8.394[2] mas/yr
Parallax (π)3.2440 ± 0.2602 mas[2]
Distance1,010 ± 80 ly
(310 ± 20 pc)
Absolute magnitude (MV)−2.67[3]
Details
Mass9.6±0.3[7] M☉
Radius8.70±0.17[8] R☉
Luminosity2,539.73[3] L☉
Surface gravity (log g)3.80±0.04[8] cgs
Temperature19,000±190[8] K
Rotational velocity (v sin i)140±3[8] km/s
Age20.4±2.3[7] Myr
Other designations
E Car, V345 Car, CPD−70°861, GC 12602, HD 78764, HIP 44626, HR 3642, SAO 256583[9]
Database references
SIMBADdata

V345 Carinae is a star in the constellation Carina. It has the Bayer designation E Carinae; V345 Carinae is the variable star designation. The star has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around +4.66.[3] Its actual brightness varies from magnitude +4.67 to +4.78 with a period of 137.7 days.[4] Based on parallax measurements, it is located at a distance of approximately 1,010 light years from the Sun.[2] It is drifting further away with a radial velocity of around +19 km/s.[3]

This star has a stellar classification of B2(IV)n,[5] matching a suspected B-type subgiant star. The 'n' notation indicates "nebulous" lines caused by rapid rotation: the star is spinning with a projected rotational velocity of 140 km/s.[8] It is a Be star having a circumstellar disk of hot, decreted gas that is inserting emission lines into the spectrum.[6] The star is 20[7] million years old with 9.6[7] times the mass of the Sun and 8.7[8] times the Sun's radius. It is radiating 2,540[3] times the luminosity of the Sun from its photosphere at an effective temperature of 19,000 K.[8]

The star displays a complex luminosity variation with a periods of 1.13028 and 137.7 days. Although thought to be a single star,[10] Carrier et al. (2002) suggested the longer period may be caused by some sort of binary interaction with the circumstellar disk or perhaps a light reflecting effect. However, no companion has been detected via radial velocity variations. This suggests that the companion would need to either have less than 1.7 times the mass of the Sun or it is being viewed from nearly pole-on.[11] The short-term variations may be from non-radial pulsations similar to those of ω CMa.[12]

  1. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference vsx was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  8. ^ a b c d e f g Cite error: The named reference Arcos2018 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Carrier2002 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Rivinius2003 was invoked but never defined (see the help page).