Star Stars · In Canis Minor
Gomeisa
Gomeisa, β Canis Minoris, is a blue-white main-sequence star in Canis Minor: the 156th brightest star in the night sky.
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- Constellation
- Canis Minor
- Designation
- β Canis Minoris
- Apparent magnitude
- 2.89 · 156th brightest star in the night sky
- Spectral class
- B8Vvar
- Distance
- 162 light-years
- Highest at midnight
- early January
- Position (J2000)
- RA 07h 27m · Dec +08° 17′
A blue-white main-sequence star, around 14,000 K, like Rigel and Spica. About 28× brighter than the faintest star the eye can see. Gives off about 140 times the Sun's visible light. The light you are seeing left around 1864.
When to see it
On the night of Sun 10 Jan 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT | 17:27 | 00:08 · 47° | 06:48 |
| New York EST | 17:35 | 00:02 · 58° | 06:30 |
| Singapore GMT+8 | 19:13 | 01:13 · 83° | 07:13 |
| Sydney GMT+11 | 19:27 | 01:04 · 48° | 06:41 |
Common questions
- Can I see it from 50° north?
- Yes. It rises and sets, and at its highest it stands 48° up in the south.
- Can I see it from 35° south?
- Yes. It rises and sets, and at its highest it stands 47° up in the north.
- When is the best time of year to see it?
- Around early January, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by mid April it is highest in the early evening, and in early October not until the hours before dawn.
- How far away is it, and how bright?
- It is 162 light-years away, and shines at magnitude 2.89 in our sky. From that far, the Sun would be a star of magnitude 8.3: too faint for the eye, a target for binoculars.
- Naked eye, binoculars or telescope?
- The naked eye, even from a city: at magnitude 2.89 it is brighter than the faintest stars a city sky still shows, about magnitude 4.5.
Look for
Start from Procyon: Gomeisa is 4.3° north-west of it, three fingers at arm’s length.
Look for
From 50° north it climbs to 48°; from 35° north it climbs to 63°; from the equator it climbs to 82°; from 35° south it climbs to 47°.
Science
Gomeisa’s surface is about 14,000 K, some 8,200 K hotter than the Sun’s 5,772 K, so its light is strongest at about 210 nm, in the ultraviolet, past the violet end of what the eye can see, 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 −0.6, about as bright as Canopus looks to us.
Did you know
Against Procyon, the brighter star the hop starts from: Procyon looks 9.9 times as bright as Gomeisa in our sky, but Procyon is 11 light-years away and Gomeisa 162 light-years, so side by side Gomeisa would give off 20 times as much light as Procyon.
Science
Gomeisa is the 75th nearest to us of the 156 stars on these pages with a measured distance. Its nearest neighbour among them in space is Alhena, about 62 light-years from it; on our sky the two are 15° apart.
Look for
The Sun passes 13° north of Gomeisa around mid July, when it is highest at noon, in daylight: the weeks either side are its worst time of year. From 50° north it is above the horizon for about 13 hours a day, from 35° north about 13 and from 35° south about 11. It is 12° from the plane of the Milky Way.