White subgiant · Delphinus
η Delphini
Also known as: η Del, HIP 101483
mag 5.4240 light-years
About
η Delphini is a white subgiant of magnitude 5.4 in Delphinus, about 240 light-years away.
How to find it
- η Delphini is in the constellation Delphinus.
- Best evenings: around mid-September 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 67° 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
- EyesNeeds a dark sky away from city lights.
- 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 Delphini (η Del) |
|---|---|
| Hipparcos number | HIP 101483 |
| Type | White subgiant |
| Spectral type | A3IVs |
| Colour | WhiteB−V colour index 0.09 |
| Magnitude | 5.4The smaller the number, the brighter. |
| Distance | 240 light-yearsThe light you see left it around 1790. |
| Proper motion | 0.080″ per year across the sky |
| Constellation | Delphinus |
| Right ascension (J2000) | 20h 33m 57.0s |
| Declination (J2000) | +13° 01′ 38″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →