12 Persei
Star in the constellation Perseus
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12 Persei (12 Per) is a double-lined spectroscopic binary star system in the northern constellation Perseus. Its combined apparent magnitude is 4.94,[3] which means it can be viewed with the naked eye. Based upon parallax measurements, this system is about 79 light years away from the Sun.[2]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Perseus[1] |
| Right ascension | 02h 42m 14.91569s[2] |
| Declination | +40° 11â² 38.1898â³[2] |
| Apparent magnitude (V) | 4.94[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | F9 V[5] |
| UâB color index | +0.08[3] |
| BâV color index | +0.56[3] |
| Astrometry | |
| Radial velocity (Rv) | â23.04±0.04[6] km/s |
| Proper motion (μ) | RA: â17.20[2] mas/yr Dec.: â183.30[2] mas/yr |
| Parallax (Ï) | 41.34±0.43 mas[2] |
| Distance | 78.9 ± 0.8 ly (24.2 ± 0.3 pc) |
| Absolute magnitude (MV) | +2.99[1] |
| Orbit | |
| Period (P) | 330.98[4] d |
| Semi-major axis (a) | 53.18[7] mas |
| Eccentricity (e) | 0.663[4] |
| Inclination (i) | 127.17[7]° |
| Details | |
| 12 Per A | |
| Mass | 1.382±0.019[4] Mâ |
| Radius | 1.55[4] Râ |
| Luminosity | 3.02[4] Lâ |
| Surface gravity (log g) | 4.20±0.10[4] cgs |
| Temperature | 6195±200[4] K |
| Metallicity [Fe/H] | â¥0.35[4] dex |
| Rotational velocity (v sin i) | 13[8] km/s |
| Age | 1.12[4] Gyr |
| 12 Per B | |
| Mass | 1.240±0.017[4] Mâ |
| Radius | 1.31[4] Râ |
| Luminosity | 1.86[4] Lâ |
| Surface gravity (log g) | 4.30±0.10[4] cgs |
| Temperature | 6000±200[4] K |
| Other designations | |
| 12 Per, BD+39° 610, FK5 2187, GJ 105.6 ÐÐ, HD 16739, HIP 12623, HR 788, SAO 55793[9] | |
| Database references | |
| SIMBAD | data |
The magnitude difference between the two components is estimated to be 0.51. Based upon this, the primary has a mass around 138% of the Sun, 155% of the Sun's radius, and shines with three times the Sun's luminosity. The smaller secondary component is also larger than the Sun, with 124% of the Sun's mass, 131% of the radius of the Sun, and has 186% of the Sun's luminosity.[4] The stellar classification of the primary is F9 V,[5] which suggests it is an F-type main sequence star. The pair have an estimated age of just over a billion years.[4]
The pair orbit each other with a period of 331 days and an eccentricity of 0.663.[4] The semimajor axis of their orbit is 1.27 AU, which means the inner stability radius for a hypothetical planet orbiting the pair would be at 4.35 AU. This lies outside the habitability zone for this system.[10]