Blue-white supergiant · Canis Major
ο² Canis Majoris
Also known as: ο² CMa, HIP 33977
mag 3.02,800 light-years
About
ο² Canis Majoris is a blue-white supergiant of magnitude 3.0 in Canis Major, about 2,800 light-years away.
How to find it
- ο² Canis Majoris is in the constellation Canis Major.
- Best evenings: around mid-February it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from south of 56° N.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesVisible from the suburbs on a clear night, but lost in bright city skies.
- Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
- Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.
Stars look the same in any instrument: brighter and sharper, but never bigger.
Facts
| Designation | ο² Canis Majoris (ο² CMa) |
|---|---|
| Hipparcos number | HIP 33977 |
| Type | Blue-white supergiant |
| Spectral type | B3Ia |
| Colour | WhiteB−V colour index −0.08 |
| Magnitude | 3.0The smaller the number, the brighter. |
| Distance | 2,800 light-yearsThe light you see left it around 700 BC. Distances this large are uncertain by 10% or more. |
| Proper motion | 0.005″ per year across the sky |
| Constellation | Canis Major |
| Right ascension (J2000) | 07h 03m 01.5s |
| Declination (J2000) | −23° 50′ 00″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →