Star Stars · In Ursa Major
Dubhe
Dubhe, α Ursae Majoris, is a yellow-white main-sequence star in Ursa Major: the 38th brightest star in the night sky.
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- Constellation
- Ursa Major
- Designation
- α Ursae Majoris
- Apparent magnitude
- 1.81 · 38th brightest star in the night sky
- Spectral class
- F7V comp
- Distance
- 123 light-years
- Highest at midnight
- early March
- Position (J2000)
- RA 11h 04m · Dec +61° 45′
A yellow-white main-sequence star, around 6,500 K, like Procyon. About 75× brighter than the faintest star the eye can see. Gives off about 230 times the Sun's visible light. The light you are seeing left around 1903.
When to see it
On the night of Fri 5 Mar 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT | Never sets | 00:11 · 80° | — |
| New York EST | Never sets | 00:06 · 69° | — |
| Singapore GMT+8 | 19:08 | 01:17 · 30° | 07:26 |
| Sydney GMT+11 | Never rises | ||
Common questions
- Can I see it from 50° north?
- Yes, on any clear night of the year. From there it never sets: it is circumpolar, circling the pole and still 22° up at its lowest.
- Can I see it from 35° south?
- No. From there it never rises: you would have to travel north of 28° south before it cleared the horizon at all.
- When is the best time of year to see it?
- Around early March, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by early June it is highest in the early evening, and in early December not until the hours before dawn.
- How far away is it, and how bright?
- It is 123 light-years away, and shines at magnitude 1.81 in our sky. From that far, the Sun would be a star of magnitude 7.7: too faint for the eye, a target for binoculars.
- Naked eye, binoculars or telescope?
- The naked eye, even from a city: at magnitude 1.81 it is brighter than the faintest stars a city sky still shows, about magnitude 4.5.
Look for
Start from Alioth: Dubhe is 15° north-west of it, a fist and a half at arm’s length.
Look for
From 50° north and 35° north it is circumpolar and never sets; from the equator it climbs to 28°; from 35° south it never rises.
Science
Dubhe’s surface is about 6,500 K, some 700 K hotter than the Sun’s 5,772 K, so its light is strongest at about 450 nm, where the Sun’s is strongest at 500 nm. Moved to 33 light-years, the distance astronomers compare stars at, it would shine at magnitude −1.1.
Did you know
Against Alioth, the brighter star the hop starts from: the two look about as bright as each other in our sky; Alioth is 83 light-years away and Dubhe 123 light-years, so side by side Dubhe would give off 2.1 times as much light as Alioth.
Science
Dubhe is the 61st nearest to us of the 156 stars on these pages with a measured distance. Its nearest neighbour among them in space is Phecda, about 44 light-years from it; on our sky the two are 10° apart.
Look for
The Sun passes 50° south of Dubhe around early September, when it is highest at noon, in daylight: the weeks either side are its worst time of year. It is 51° from the plane of the Milky Way, well away from the band.