Vela was originally part of the ancient constellation Argo Navis – named after the ship Argo which was sailed by Jason and the Argonauts on their expedition in search of the golden fleece (the rays of the sun). Nicolas Louis de Lacaille separated Argo Navis into three constellations in 1763, Vela, Carina and Puppis. Some sources say it was divided into 4 the other being Pyxis the magnetic compass which couldn’t have been part of the ship Argo, because in those ancient times the ship would not have had a magnetic compass. When Argo Navis was split up, the Greek letters labelling the stars remained the same and were divided between the 3 constellations. Therefore gamma (γ) is the first star in Vela.
Vela with an area of approximately 500 square degrees, is found in the southern sky and is easily spotted by looking for the False Cross which is half as large again as the Southern Cross and lies approximately 35 degrees southwest of the Southern Cross. The false cross is marked by the stars kappa (κ) and delta (δ) Velorum in Vela and epsilon and iota Carinae.
Vela is almost completely within the Milky Way so it has many emission and reflection nebulae, over 40 open clusters, many double stars, several planetary nebulae and only one Globular cluster. Listed below are a few of the things worthwhile having a look at with binoculars or an average amateur telescope.
Delta Vel (δ) is a 1.9 mag star with a 5.1 mag companion which the literature suggests can be split with 100mm aperture, but I could not split it with the C8 (200mm).
γ Velorum (gamma) is a spectacular multiple star – binoculars can just split a double, and with just 37x magnification in my 78mm scope a nice group of two pairs forming a Y shape is visible, (see drawing) at 105x it is even more stunning. The brightest of the components a blue-white magnitude 1.8 star is the brightest Wolf-Rayet star known. (Wolf-Rayet stars are rare luminous blue stars which are thought to eject matter at high velocities from their very hot surface. They are considered unstable bodies on the brink of blasting apart and becoming a supernova).
λ Lamda Vel. is a bright orange mag. 2.2 supergiant.
IC 2391 is my favourite open cluster in Vela. It surrounds the variable mag. 3.6 Omicron Velorum, visible as a small hazy patch with the naked eye south west of Delta. A good binocular object showing approx. 20 stars with a distinct central pattern shaped like a bucket which Delta appears to be dropping towards – use your imagination (see drawing of binocular view), also good at low magnification with a small telescope– the C8 with only 51 x magnification was too much the cluster was lost, the 78mm Takahashi at 37x was better.
IC 2669 is a mag. 6.1 open cluster near 2391.
NGC2547 is another open cluster 17’across, a good binocular subject, can you see a miniature of Crux within the cluster?
NGC3132 Eight – burst planetary nebula at mag. 8 with a 10th mag. central star is 1 arc min. across and lies on the border of Vela and Antlia. The appearance that several outbursts of gaseous material had emerged from the central star gives it it’s name. Unlike other planetaries, I have observed it as bright white and doesn’t have that greenish or blue glow. It is just visible with the 78mm at 37x although very faint with averted vision; increasing the magnification to 74x a faint fuzzy glow is visible, but the central star is not seen. With the C8 at 240x the bright white central star is seen with a white glow around it. It was easy to locate with the “Argo Navis” guide on the C8, more of a challenge to find with the Takahashi and telrad but worth the time spent searching.
NGC3201 the only globular cluster, approximately 5’ across, is mag. 6.8 and requires 105mm aperture to observe.
The Gum Nebula is named after the Australian astronomer Colin S. Gum who, on long exposure photos in the 1950’s detected long filaments with stars strung out on them like beads on a string. The Gum is thought to be the remains of one or more supernovae. The Vela Supernova Remnant, the largest Super Nova Remnants and one of few visible to the naked eye, is superimposed on the Gum Nebula. It is best viewed with an OIII filter to bring out the nebulosity. Have any of those disappointed Star Party shoppers found a source to purchase one yet?
Information sourced from: my telescope; Collins Stars & Planets, 3rd Edition; Hartung’s Astronomical Objects for Southern Telescopes; Sky watching by Levy.