GX Velorum

GX Velorum
Location of GX Velorum (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Vela
Right ascension 09h 11m 04.39802s[1]
Declination −44° 52′ 04.4411″[1]
Apparent magnitude (V) +4.99[2] (4.97 to 5.04)[3]
Characteristics
Spectral type B5 Ia[4]
U−B color index −0.57[5]
B−V color index +0.22[5]
Variable type α Cyg?[3]
Astrometry
Radial velocity (Rv)+28.2±0.8[6] km/s
Proper motion (μ) RA: −5.608[1] mas/yr
Dec.: +3.843[1] mas/yr
Parallax (π)0.7696 ± 0.1585 mas[1]
Distanceapprox. 4,200 ly
(approx. 1,300 pc)
Absolute magnitude (MV)−7.20[7]
Details[8]
Mass35 M☉
Radius61±7[9] R☉
Luminosity214,000[9] L☉
Surface gravity (log g)2.12±0.05[9] cgs
Temperature15,000±150[9] K
Rotational velocity (v sin i)39 km/s
Age8.3[10] Myr
Other designations
GX Vel, CD−44°5206, HD 79186, HIP 45085, HR 3654, SAO 220928[11]
Database references
SIMBADdata

GX Velorum is a solitary[12] variable star[3] in the southern constellation of Vela. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude that fluctuates around 4.99.[2] Based upon parallax measurements, it is located approximately 4,200 light years distant from the Sun, and is drifting further away with a radial velocity of +28 km/s.[6] It may be a member of the Vela OB1 association of co-moving stars.[7]

A light curve for GX Velorum, plotted from Hipparcos data[13]

This object is a massive blue supergiant with a stellar classification of B5 Ia.[4] It is suspected to be an Alpha Cygni-type pulsating variable and ranges in brightness from 4.97 down to 5.04 magnitude.[3] It is losing mass at the rate of (0.40±0.02)×10−6 M☉ yr−1,[9] or one solar mass every 2.5 million years. The star is 8.3[10] million years old with 35 times the mass of the Sun.[8] It has expanded to around 61[9] times the Sun's radius and is radiating 214,000[9] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 15,000 K.[9]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference ducati was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference reed was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference fraser was invoked but never defined (see the help page).
  9. ^ a b c d e f g h Cite error: The named reference Haucke2018 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference tetzlaff was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).