GX Velorum
Star in the constellation Vela
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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]
  | |
| 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] |
| Distance | approx. 4,200 ly (approx. 1,300 pc) |
| Absolute magnitude (MV) | −7.20[7] |
| Details[8] | |
| Mass | 35 M☉ |
| Radius | 61±7[9] R☉ |
| Luminosity | 214,000[9] L☉ |
| Surface gravity (log g) | 2.12±0.05[9] cgs |
| Temperature | 15,000±150[9] K |
| Rotational velocity (v sin i) | 39 km/s |
| Age | 8.3[10] Myr |
| Other designations | |
| GX Vel, CD−44°5206, HD 79186, HIP 45085, HR 3654, SAO 220928[11] | |
| Database references | |
| SIMBAD | data |
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]