Constellation, UMa
Ursa Major: the Great Bear
Ursa Major covers 1,279 square degrees of sky, the 3rd largest of the 88. Its brightest star is Alioth. It is best placed in the evening sky in April.
Show Ursa Major in the live sky
Ursa Major at a glance
| Fact | Value |
|---|---|
| IAU abbreviation | UMa |
| Meaning | the Great Bear |
| Pronounced | ER-suh MAY-jur |
| Genitive, used in star names | Ursae Majoris (for example a Bayer name such as α Ursae Majoris) |
| Area | 1,279 square degrees, number 3 of 88 by size |
| Stars to magnitude 6 in our catalogue | 122 |
| Brightest star | Alioth, magnitude 1.8 |
| Best seen | Evenings in April, when it is highest at 9 pm |
| Declination range | 28° to 73° |
| Borders | Draco, Canes Venatici, Lynx, Leo Minor, Camelopardalis, Leo, Boötes, Coma Berenices |
Where on Earth you can see Ursa Major
Ursa Major spans declinations 28° to 73°. Every part of it rises above the horizon at some moment for observers between latitudes 17°S and 90°N. Some of it can be seen from latitudes 62°S to 90°N. North of 62°N none of it ever sets. This is geometry only: it ignores haze, hills and buildings near the horizon.
From six cities
| City | Latitude | Visibility | Middle at its highest |
|---|---|---|---|
| Pune | 18.5°N | All of it rises | 54° |
| New York | 40.7°N | All of it rises | 77° |
| London | 51.5°N | All of it rises | 87° |
| Tromsø | 69.6°N | Never sets | 74° |
| Tokyo | 35.7°N | All of it rises | 72° |
| Sydney | 33.9°S | Only part of it rises | 2° |
Ursa Major's named stars
These stars in Ursa Major have names approved by the IAU Working Group on Star Names. Magnitude is brightness: a lower number is brighter, and the faintest stars seen with the naked eye on a dark night are about magnitude 6.
| Star | Designation | Magnitude | Distance (light-years) |
|---|---|---|---|
| Alioth | ε Ursae Majoris | 1.76 | 82.6 |
| Dubhe | α Ursae Majoris | 1.81 | 120 |
| Alkaid | η Ursae Majoris | 1.85 | 100 |
| Mizar | ζ Ursae Majoris | 2.23 | 85.8 |
| Merak | β Ursae Majoris | 2.34 | 79.7 |
| Phecda | γ Ursae Majoris | 2.41 | 83.2 |
| Tania Australis | μ Ursae Majoris | 3.06 | 230 |
| Talitha | ι Ursae Majoris | 3.12 | 47.3 |
| Megrez | δ Ursae Majoris | 3.32 | 80.5 |
| Muscida | ο Ursae Majoris | 3.35 | 180 |
| Tania Borealis | λ Ursae Majoris | 3.45 | 140 |
| Alula Borealis | ν Ursae Majoris | 3.49 | 400 |
| Alkaphrah | κ Ursae Majoris | 3.57 | 360 |
| Taiyangshou | χ Ursae Majoris | 3.69 | 180 |
| Alula Australis | ξ Ursae Majoris | 3.79 | not known |
| Alcor | 80 Ursae Majoris | 3.99 | 81.7 |
| Chalawan | 47 Ursae Majoris | 5.03 | 45.9 |
| Intercrus | HR 3743 | 5.40 | 280 |
Distances are about, from the HYG database (Hipparcos parallax), and "not known" means the catalogue has no reliable parallax for that star.
How these facts were found
The name, meaning and boundaries are the IAU's. Area, borders and the latitude ranges are computed from those boundaries; the brightest star and the star count come from a magnitude-6 star catalogue; star names are matched to the catalogue by Hipparcos number and checked by position. The month is when Ursa Major's middle crosses the north-south line of the sky at 9 pm local solar time. See How we know.
Sources
- IAU: The Constellations. Names, meanings, pronunciations and boundaries
- IAU Working Group on Star Names. The official names of stars
- astronomy-engine. The MIT licensed library that does the calculations, run on the page's build machine and in the app
- HYG database v4.4 (astronexus). Distances, spectral types and luminosities, licence CC BY-SA 4.0