Blue-white subgiant · Crux
Acrux
Also known as: α¹ Crucis (α¹ Cru), HIP 60718
mag 0.8320 light-years
About
Acrux (α¹ Crucis) is a blue-white subgiant of magnitude 0.8 in Crux, about 320 light-years away.
How to find it
- Acrux is in the constellation Crux.
- Best evenings: around mid-May 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 17° N.
- Star patterns: Southern Cross and the Pointers.
- Southern Cross and the Pointers: The foot of the cross; a small telescope splits it into two blue-white stars.
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
- EyesA first-magnitude star, obvious even from a city. It looks blue-white.
- Binoculars (10×50)Dazzling, with its colour stronger than to the eye.
- 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
| Proper name | Acrux |
|---|---|
| Designation | α¹ Crucis (α¹ Cru) |
| Hipparcos number | HIP 60718 |
| Type | Blue-white subgiant |
| Spectral type | B0.5IV |
| Colour | Blue-whiteB−V colour index −0.24 |
| Magnitude | 0.8The smaller the number, the brighter. |
| Distance | 320 light-yearsThe light you see left it around 1700. |
| Proper motion | 0.038″ per year across the sky |
| Constellation | Crux |
| Right ascension (J2000) | 12h 26m 35.9s |
| Declination (J2000) | −63° 05′ 57″ |
More in Crux
NGC 4755Jewel BoxOpen cluster · mag 4.2
NGC 4609Coalsack ClusterOpen cluster · mag 6.9
C99Coalsack NebulaDark nebula
NGC 4103The LongtailOpen cluster · mag 7.4Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →