Mu Cassiopeia ( μ Cas ) is a binary star with components of the spectral class G5 and M5 (and weighing 60% and 15% of the solar). It has its own name Marfak from the Arabic Mirfaq - "elbow". Ptolemy in the Almagest is missing.
| Mu Cassiopeia AB | |||
|---|---|---|---|
| Double star | |||
| Observational data ( Age J2000.0 ) | |||
| Right ascension | |||
| Declination | |||
| Distance | 24.6 ± 0.1 St. years (7.54 ± 0.03 pc ) | ||
| Visible magnitude ( V ) | 5.17 / 11 | ||
| Constellation | Cassiopeia | ||
| Astrometry | |||
| Radial velocity ( R v ) | -98.1 km / s | ||
| Own movement (μ) | RA: 3,421.44 mas per year Dec: -1,599.27 mas per year | ||
| Parallax (π) | 132.57 ± 0.57 mas | ||
| Absolute magnitude (V) | 5.78 / 11.6 | ||
| Specifications | |||
| Spectral class | G5VIp / M5V | ||
| Color Index ( B - V ) | 0.10 | ||
| Color Index ( U - B ) | 0.69 | ||
| physical characteristics | |||
| Weight | 0.60 / 0.17 M ☉ | ||
| Radius | 0.74 / 0.29 R ☉ | ||
| Age | 7.9⋅10 9 years | ||
| Temperature | 5290 K | ||
| Luminosity | 0.46 / 0.00 L ☉ | ||
| Metallicity | [M / H] = 13-28% | ||
| Elements of the orbit | |||
| Period ( P ) | 21.40 years | ||
| Semimajor axis ( a ) | 0.189 " | ||
| Eccentricity ( e ) | 0.62 | ||
| Inclination ( i ) | 110.0 ° v | ||
| Node (Ω) | 227.3 ° | ||
| Periastric Age ( T ) | 1975.80 | ||
| |||
| Database Information | |||
| SIMBAD | |||
The stars μ Cas A and B orbit at a distance of 1.42 a. e. with a period of 21.4 years. The second component of the star was discovered by Nicholas Wagman in 1961-1962. (Nicholas E. Wagman (1905-1980)). For the first time in the star catalogs, μ Cas was listed by Tycho Brahe.
Stars fly through the Galaxy at a speed of 167 km / s. Astronomers believe that using modern tools to register exoplanets the size of the Earth in this system is very difficult.
Content
μ Cas A
This star is a yellow dwarf of the main sequence , similar to our Sun. It has a mass of 74% of the mass of the Sun, 82% of its diameter and 42% of its luminosity.
μ Cas B
Red dying star. It is also a dwarf , like μ Cas A. It has only 15-17% of the mass of the Sun and 29% of its diameter.
Nearest star environment
The following star systems are within 20 light-years of μ Cassiopeia:
| Star | Spectral class | Distance, st. years old |
| η Cassiopeia AB | F9-G0V / K7 V | 5,4 |
| Wolf 47 AB | M2 Ve / M7 V | 6.8 |
| BD + 56 ° 2966 | K3 V | 7.2 |
| AC + 71 532 | M3.5 Ve | 7.7 |
| BD + 63 ° 238 | K0 v | 9.3 |
| Gliese 3126 | M4 v | 9.6 |