Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Perseus |
Right ascension | 02h 44m 11.98704s[1] |
Declination | +49° 13′ 42.4111″[1] |
Apparent magnitude (V) | 4.11[2] / 9.987[3] |
Characteristics | |
θ Per A | |
Evolutionary stage | Main sequence |
Spectral type | F8 V[4] |
U−B color index | +0.00[5] |
B−V color index | +0.49[5] |
θ Per B | |
Spectral type | M1.5 V[6] |
B−V color index | +1.48[7] |
Astrometry | |
Radial velocity (Rv) | +24.32[8] km/s |
Proper motion (μ) | RA: +334.66[1] mas/yr Dec.: -89.99[1] mas/yr |
Parallax (π) | 89.87 ± 0.22 mas[1] |
Distance | 36.29 ± 0.09 ly (11.13 ± 0.03 pc) |
Absolute magnitude (MV) | 3.88[9] |
Orbit[10] | |
Period (P) | 2,720 yr |
Semi-major axis (a) | 22.289″ |
Eccentricity (e) | 0.13 |
Inclination (i) | 75.44° |
Longitude of the node (Ω) | 128° |
Periastron epoch (T) | B 1613 |
Argument of periastron (ω) (secondary) | 100.64° |
Details | |
θ Per A | |
Mass | 1.138±0.010[11] M☉ |
Radius | 1.319±0.011[11] R☉ |
Luminosity | 2.235±0.040[11] L☉ |
Surface gravity (log g) | 4.43±0.17[12] cgs |
Temperature | 6,328±86[12] K |
Metallicity [Fe/H] | −0.03±0.09[12] dex |
Age | 4.0±0.4[11] Gyr |
θ Per B | |
Mass | 0.521±0.052[3] M☉ |
Radius | 0.498±0.017[3] R☉ |
Temperature | 3,685±60[3] K |
Metallicity [Fe/H] | −0.03±0.09[12] dex |
Age | 2.4[3] Gyr |
Other designations | |
θ Per A: 13 Persei, HR 799, HD 16895, HIP 12777, FK5 93, GC 3277, PPM 45428, SAO 38288 | |
θ Per B: 2MASS J02441025+4913540 | |
Database references | |
SIMBAD | θ Per |
θ Per A | |
θ Per B |
Theta Persei (Theta Per, θ Persei, θ Per) is a star system 37 light years away from Earth, in the constellation Perseus. It is one of the closest naked-eye stars.
The primary star is a yellowish dwarf (main sequence) star of spectral type F8V, which is somewhat larger and brighter than the Sun, but still within the range considered to have the potential for Earth-like planets. There is also a red dwarf companion of spectral type M1.V, orbiting about 250 AU from the primary. It has a Gaia Data Release 2 parallax of 89.2871±0.1534 mas, corresponding to a distance of 11.2 pc.[13]
An 11th-magnitude star is listed in double-star catalogues as component C of the multiple system. It was 95″ away from component A in 2002,[14] although the separation is rapidly increasing as it is a distant background object with a very different proper motion to the other two stars.[15] An unconfirmed companion, possibly a brown dwarf, was reported 6.2″ from θ Persei B in 2010.[16]
van Leeuwen2007
was invoked but never defined (see the help page).vanbelle
was invoked but never defined (see the help page).Mann
was invoked but never defined (see the help page).mk
was invoked but never defined (see the help page).bsc
was invoked but never defined (see the help page).carmenes
was invoked but never defined (see the help page).weis
was invoked but never defined (see the help page).apjss141
was invoked but never defined (see the help page).Holmberg2009
was invoked but never defined (see the help page).Boule
was invoked but never defined (see the help page).apj746_1_101
was invoked but never defined (see the help page).bonfils
was invoked but never defined (see the help page).dr2b
was invoked but never defined (see the help page).wds
was invoked but never defined (see the help page).dr2c
was invoked but never defined (see the help page).tanner
was invoked but never defined (see the help page).