Blue-white main-sequence star · Monoceros
β Monocerotis
Also known as: β Mon, HIP 30867
mag 3.8680 light-years
About
β Monocerotis is a blue-white main-sequence star of magnitude 3.8 in Monoceros, about 680 light-years away.
How to find it
- β Monocerotis is in the constellation Monoceros.
- 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 73° 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 | β Monocerotis (β Mon) |
|---|---|
| Hipparcos number | HIP 30867 |
| Type | Blue-white main-sequence star |
| Spectral type | B3Ve |
| Colour | Blue-whiteB−V colour index −0.11 |
| Magnitude | 3.8The smaller the number, the brighter. |
| Distance | 680 light-yearsThe light you see left it around 1350. |
| Proper motion | 0.009″ per year across the sky |
| Constellation | Monoceros |
| Right ascension (J2000) | 06h 28m 49.1s |
| Declination (J2000) | −07° 01′ 59″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →