Blue-white giant · Perseus
δ Persei
Also known as: δ Per, HIP 17358
mag 3.0520 light-years
About
δ Persei is a blue-white giant of magnitude 3.0 in Perseus, about 520 light-years away.
How to find it
- δ Persei is in the constellation Perseus.
- 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 north of 32° S.
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 | δ Persei (δ Per) |
|---|---|
| Hipparcos number | HIP 17358 |
| Type | Blue-white giant |
| Spectral type | B5III SB |
| Colour | Blue-whiteB−V colour index −0.12 |
| Magnitude | 3.0The smaller the number, the brighter. |
| Distance | 520 light-yearsThe light you see left it around 1510. |
| Proper motion | 0.048″ per year across the sky |
| Constellation | Perseus |
| Right ascension (J2000) | 03h 42m 55.5s |
| Declination (J2000) | +47° 47′ 15″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →