White main-sequence star · Ursa Minor
Yildun
Also known as: δ Ursae Minoris (δ UMi), HIP 85822
mag 4.4170 light-years
About
Yildun (δ Ursae Minoris) is a white main-sequence star of magnitude 4.4 in Ursa Minor, about 170 light-years away.
How to find it
- Yildun is in the constellation Ursa Minor.
- Where on Earth: it is seen well, at least 10° up, from north of 7° N.
- Star patterns: Little Dipper.
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
| Proper name | Yildun |
|---|---|
| Designation | δ Ursae Minoris (δ UMi) |
| Hipparcos number | HIP 85822 |
| Type | White main-sequence star |
| Spectral type | A1Vn |
| Colour | WhiteB−V colour index 0.02 |
| Magnitude | 4.4The smaller the number, the brighter. |
| Distance | 170 light-yearsThe light you see left it around 1850. |
| Proper motion | 0.055″ per year across the sky |
| Constellation | Ursa Minor |
| Right ascension (J2000) | 17h 32m 12.9s |
| Declination (J2000) | +86° 35′ 11″ |
More in Ursa Minor
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →