About Mirach
Description
Mirach is a red giant of spectral type M0IIIa at magnitude 2.06 in Andromeda. Located about 197 light-years from Earth, it has a luminosity of roughly 1,900 times solar and a diameter about 100 times the Sun's. Its warm reddish-orange color is easily noticeable to the naked eye.
Observing Tips
Mirach is the middle of the three bright stars forming the main chain of Andromeda, northeast of the Great Square of Pegasus. It is a useful guide to M31 — the Andromeda Galaxy lies about 8 degrees northwest of Mirach, found by turning right from the Mirach-Mu And line. Its distinctive red-orange color helps identify it. Best observed September through January.
History
The name Mirach derives from the Arabic 'mi'zar,' meaning 'the girdle' or 'waistcloth.' In some traditions it was called 'the Belt of Andromeda.' Mirach has been a key guide star for finding the Andromeda Galaxy since the earliest days of deep-sky astronomy.
Fun Facts
Mirach has a small galaxy (NGC 404, nicknamed 'Mirach's Ghost') just 7 arcminutes away, easily visible in a small telescope. The glow of Mirach makes this faint galaxy hard to spot, giving it its ghostly nickname.
Observe
1Physical Properties
2Position & Identifiers
3How easy to spot?
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Easy | Easy | Easy |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Survey Image
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Explore
7
Size Comparison
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
15
Exoplanets
1 known planet
View in 3D
| Planet | Radius | Mass | Period | Distance |
|---|---|---|---|---|
| HD 6860 b | 11.90R⊕ | 28.26M♃ | 1.8yr | 199ly |
Habitable Zone
Size & Mass Comparison
About exoplanets — how we find them and which host stars you can observe
Discover
16Stellar Notes
17
Light Travel Time Machine
18
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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