File:Cepheus_constellation_map.svg · Wikimedia Commons · See Wikimedia Commons
Mu Cephei
Sign in to saveAlso known as mu. Cep, Erakis, μ Cep, μ Cephei, ADS 15271 A, HIP 107259, HIC 107259, HR 8316
star in the constellation Cepheus
Astronomical data · SIMBAD
- Object type
- s*r
- Spectral type
- M2-Ia
- Distance
- 27,408 light-years
- Redshift
- z = 0.00007672268508085445
- Coordinates
- RA 325.8769° · Dec 58.7800°
via SIMBAD · CDS Strasbourg
Key facts
- Constellation
- Cepheus
- Right ascension
- 21 43 30.460
- Declination
- +58 ° 46 ′ 48.17 ″
- Apparent magnitude v
- 3.43–5.1
- Evolutionary stage
- Red supergiant or red hypergiant
- Spectral type
- M2-Ia (M2e Ia or M2 Ia+ )
- U b color index
- +2.42
- B v color index
- +2.35
- Variable type
- SRc
via Wikipedia infobox
Wikidata facts
- Constellation
- Cepheus
- Radius
- 1455
- Image
- Mu Cephei "The Garnet Star" 2023 (Ha and OIII).png
Show 13 more facts
- spectral class
- M2I
- catalog code
- AG+58 1378
- Commons category
- Mu Cephei
- apparent magnitude
- -1.72
- right ascension
- 325.87692107250
- declination
- 58.78004449472
- parallax
- 0.119
- radial velocity
- 19.3
- right ascension component of proper motion
- 3.439
- epoch
- J2000.0
- absolute magnitude
- -7.63
- declination component of proper motion
- -4.108
- different from
- MY Cephei
Sources (2)
via Wikidata · CC0
~7 min read
Encyclopedic overview
Mu Cephei is a red supergiant or hypergiant star in the northern constellation Cepheus. It is officially named the Garnet Star; Mu Cephei is its Bayer designation, which is Latinized from μ Cephei and abbreviated Mu Cep or μ Cep. This star appears garnet red and is located at the edge of the IC 1396 nebula. It is a 4th magnitude star easily visible to the naked eye under good observing conditions. Since 1943, the spectrum of this star has served as a spectral standard by which other stars are classified.
Mu Cephei is more than 100,000 times brighter than the Sun, with an absolute visual magnitude of −7.6. It is one of the largest known stars and also one of the most luminous and massive of its kind, with a radius around or over 1,000 times that of the Sun (R☉), and were it placed in the Sun's position, it would engulf the orbits of Mars and Jupiter.
Excerpted from Wikipedia’s “Mu Cephei” article, available under the CC BY-SA 4.0 licence.