Star Stars · In Andromeda
Mirach
Mirach, β Andromedae, is a red giant in Andromeda: the 57th brightest star in the night sky.
Save the chart (SVG) Tactile chart (A4 SVG)
- Constellation
- Andromeda
- Designation
- β Andromedae
- Apparent magnitude
- 2.07 · 57th brightest star in the night sky
- Spectral class
- M0IIIvar
- Distance
- 197 light-years
- Highest at midnight
- early October
- Position (J2000)
- RA 01h 10m · Dec +35° 37′
A red giant, around 3,700 K, like Betelgeuse and Antares. About 59× brighter than the faintest star the eye can see. Gives off about 460 times the Sun's visible light. The light you are seeing left around 1829.
When to see it
On the night of Wed 6 Oct 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT+1 | 14:51 | 01:10 · 74° | 11:28 |
| New York EDT | 16:32 | 01:04 · 85° | 09:36 |
| Singapore GMT+8 | 19:12 | 01:15 · 56° | 07:18 |
| Sydney GMT+11 | 21:02 | 01:06 · 20° | 05:10 |
Common questions
- Can I see it from 50° north?
- Yes. It rises and sets, and at its highest it stands 76° up in the south.
- Can I see it from 35° south?
- Yes. It rises and sets, and at its highest it stands 19° up in the north.
- When is the best time of year to see it?
- Around early October, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by early January it is highest in the early evening, and in early July not until the hours before dawn.
- How far away is it, and how bright?
- It is 197 light-years away, and shines at magnitude 2.07 in our sky. From that far, the Sun would be a star of magnitude 8.7: too faint for the eye, a target for binoculars.
- Naked eye, binoculars or telescope?
- The naked eye, even from a city: at magnitude 2.07 it is brighter than the faintest stars a city sky still shows, about magnitude 4.5.
Look for
Start from Hamal: Mirach is 17° north-west of it, a fist and a half at arm’s length.
Look for
From 50° north it climbs to 76°; from 35° north it climbs to 89°; from the equator it climbs to 54°; from 35° south it climbs to 19°.
Science
Mirach’s surface is about 3,700 K, some 2,100 K cooler than the Sun’s 5,772 K, so its light is strongest at about 780 nm, in the infrared, past the red 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 −1.8, brighter than Sirius, the brightest star in our sky.
Did you know
Against Hamal, the brighter star the hop starts from: the two look about as bright as each other in our sky; Hamal is 66 light-years away and Mirach 197 light-years, so side by side Mirach would give off 8.5 times as much light as Hamal.
Science
Mirach is the 84th nearest to us of the 156 stars on these pages with a measured distance. Its nearest neighbour among them in space is Schedar, about 85 light-years from it; on our sky the two are 21° apart.
Look for
The Sun passes 26° south of Mirach around early April, 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 20 hours a day, from 35° north about 16 and from 35° south about 8. It is 27° from the plane of the Milky Way.