Gamma Velorum is the brightest star in the constellation Vela;
in fact, it is a spectacular and complex multiple star system.
The brightest component, known as Gamma2 Velorum or Gamma Velorum
A is itself a spectroscopic binary consisting
of the closest known Wolf-Rayet star to
Earth and a massive blue giant or blue supergiant (spectral type O7.5Ie) orbiting around each other with a period of 78.5
days at a mean separation of 1 AU (the distance of Earth from the Sun).
The hot evolved O star is about 25 times as
massive than the Sun and some 200,000 times more luminous with a surface
temperature of 35,000 K. Its Wolf-Rayet partner, which is 50,000 times as
luminous as the Sun and has a surface temperature of 60,000 K, probably
started out with a mass of about 40 times that of the Sun but has shed much
of that original material to be left with only about 10 solar masses today.
|Gamma Velorum is the bright star to the left of center.
It is unconnected with the Gum Nebula,
which lies in the background. Credit: Southernskyphoto
Closest to Gamma2 is the bright (apparent magnitude +4.3) Gamma1 Velorum (Gamma Velorum B), a blue-white subgiant B
star. Gamma1 lies 41.2 arcseconds from the Wolf-Rayet binary,
a separation easily resolvable with binoculars. Gamma Velorum also has several
fainter companions. Gamma Velorum C, a white A
star (magnitude +8.5) is separated by 62.3 arcsec from Gamma2,
while the binary pair Gamma Velorum D and E lies 93.5 arcsec away . The
D component is another A star (magnitude of +9.4); its companion is a 13th
magnitude star, separated by 1.8 arcsec.
Gamma2 Velorum may be a member of the Vela OB2 association of
||WR8 + O7.5Ie
||840 light-years (258 pc)
||R.A. 08h 09m 32.00s, Dec. -47° 20' 12.0"
||Regor, Suhail, Suhail Al-Muhlif, HR 3207, CD -46°3846/3847,
HD 68273, SAO 219504, FK5 309, GC 11105, HIP 39953
|Components of the Gamma Velorum system
respect to (other component)
|A (Gamma2) HD68273
|B (Gamma1) HD68243