Mu Cassiopeiae
 Star map of Cassiopeia. Mu Cassiopeiae is circled. |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 01h 08m 16.39470s[1] |
| Declination | +54° 55′ 13.2264″[1] |
| Apparent magnitude (V) | 5.159[2]/11 |
| Characteristics | |
| Spectral type | G5VIp/M5V |
| U−B color index | +0.10[3] |
| B−V color index | +0.70[3] |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −98.3[2] km/s |
| Proper motion (μ) | RA: 3,422.23[1] mas/yr Dec.: −1,598.93[1] mas/yr |
| Parallax (π) | 132.38 ± 0.82[1] mas |
| Distance | 24.6 ± 0.2 ly (7.55 ± 0.05 pc) |
| Absolute magnitude (MV) | 5.77[2]/11.6 |
| Orbit[4] | |
| Companion | μ Cas B |
| Period (P) | 21.75 yr |
| Semi-major axis (a) | 1.01" |
| Eccentricity (e) | 0.56 |
| Inclination (i) | 110° |
| Longitude of the node (Ω) | 47.3° |
| Periastron epoch (T) | 1975.74 |
| Argument of periastron (ω) (secondary) |
152.7° |
| Details | |
| Mass | 0.74/0.17[4] M☉ |
| Radius | 0.791 ± 0.008[5]/0.29 R☉ |
| Luminosity | 0.442 ± 0.014[5]/0.001 L☉ |
| Surface gravity (log g) | 4.51[6] cgs |
| Temperature | 5,332[6] K |
| Metallicity [Fe/H] | −0.84[6] dex |
| Rotational velocity (v sin i) | 8[7] km/s |
| Age | 3.1[2]–5.9[8] Gyr |
| Other designations | |
Mu Cassiopeiae (μ Cas, μ Cassiopeiae) is a binary star system in the constellation Cassiopeia. This system shares the name Marfak with Theta Cassiopeiae, and the name was from Al Marfik or Al Mirfaq (المرفق), meaning "the elbow".[9]
In 1961 the close binary nature of this system was discovered by Nicholas E. Wagman at the Allegheny Observatory.[10] Since then the orbital elements of the two stars have been fairly well established. The two stars are separated by a semimajor axis of 7.61 AUs with distance range of 3.3-11.9 AUs.[citation needed] In 1966, the individual components were first resolved by the American astronomer Peter A. Wehinger using the 84-inch reflector at the Kitt Peak National Observatory, allowing an initial estimate of separate masses.[11]
Compared to other nearby stars, this pair are moving at a relatively high velocity of 167 km/s through the Milky Way galaxy. They are low metal, Population II stars that are thought to have formed before the galactic disk first appeared.
This star will be in constellation Perseus around 5200 AD.[12]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 6.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ p. 296, Patrick Moore's Data Book of Astronomy, Patrick Moore and Robin Rees, Cambridge, Cambridge University Press, 2011.
External links
- Lua error in package.lua at line 80: module 'strict' not found.
- SolStation entry
- Mu Cassiopeiae by Professor Jim Kaler.
