Blue-white main-sequence star · Centaurus
η Centauri
Also known as: η Cen, HIP 71352
mag 2.3310 light-years
About
η Centauri is a blue-white main-sequence star of magnitude 2.3 in Centaurus, about 310 light-years away.
How to find it
- η Centauri is in the constellation Centaurus.
- Best evenings: around mid-June 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 38° 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
- EyesEasy, even from town. It looks blue-white.
- 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 | η Centauri (η Cen) |
|---|---|
| Hipparcos number | HIP 71352 |
| Type | Blue-white main-sequence star |
| Spectral type | B1Vn + A |
| Colour | Blue-whiteB−V colour index −0.16 |
| Magnitude | 2.3The smaller the number, the brighter. |
| Distance | 310 light-yearsThe light you see left it around 1720. |
| Proper motion | 0.048″ per year across the sky |
| Constellation | Centaurus |
| Right ascension (J2000) | 14h 35m 30.4s |
| Declination (J2000) | −42° 09′ 28″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →