Orange giant · Horologium
α Horologii
Also known as: α Hor, HIP 19747
mag 3.9120 light-years
About
α Horologii is an orange giant of magnitude 3.9 in Horologium, about 120 light-years away.
How to find it
- α Horologii is in the constellation Horologium.
- Best evenings: around early January 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
- 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 | α Horologii (α Hor) |
|---|---|
| Hipparcos number | HIP 19747 |
| Type | Orange giant |
| Spectral type | K1III |
| Colour | Pale orangeB−V colour index 1.08 |
| Magnitude | 3.9The smaller the number, the brighter. |
| Distance | 120 light-yearsThe light you see left it around 1910. |
| Proper motion | 0.21″ per year across the sky |
| Constellation | Horologium |
| Right ascension (J2000) | 04h 14m 00.1s |
| Declination (J2000) | −42° 17′ 40″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →