HIP 57050
Star in the constellation Ursa Major / From Wikipedia, the free encyclopedia
HIP 57050, or GJ 1148, is a faint star with two orbiting exoplanets in the northern constellation of Ursa Major. Other designations for this star include LHS 2443, G 122-40, and Ross 1003.[10] From a distance of 36 light years based on parallax measurements, it is drifting closer to the Sun with a radial velocity of -9 km/s.[2] This is a faint star with an absolute magnitude of 11.64.[1] At the distance of HIP 57050, the apparent visual magnitude is 11.86,[1] which is much too faint to be seen with the naked eye. HD 164595 has a high proper motion, traversing the celestial sphere at an angular rate of 0.577″ yr−1.[11]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ursa Major[1] |
Right ascension | 11h 41m 44.63584s[2] |
Declination | +42° 45′ 07.1021″[2] |
Apparent magnitude (V) | 11.86[1] |
Characteristics | |
Spectral type | M4.0V[3] |
U−B color index | +1.52[4] |
B−V color index | +1.503±0.012[1] |
V−R color index | +1.19[4] |
Astrometry | |
Radial velocity (Rv) | −8.99±0.0014[5] km/s |
Proper motion (μ) | RA: −575.528(26) mas/yr[2] Dec.: −89.799(25) mas/yr[2] |
Parallax (π) | 90.6896 ± 0.0258 mas[2] |
Distance | 35.96 ± 0.01 ly (11.027 ± 0.003 pc) |
Absolute magnitude (MV) | 11.64[1] |
Details | |
Mass | 0.357±0.013[6] M☉ |
Radius | 0.4[7] R☉ |
Luminosity | 0.01486[7] L☉ |
Surface gravity (log g) | 4.67[7] cgs |
Temperature | 3,236±18[5] K |
Metallicity [Fe/H] | 0.32±0.06[7] dex |
Rotation | 71.5±5.1 d[8] |
Rotational velocity (v sin i) | 2.0[5] km/s |
Age | 4.44±0.016[9] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
The spectrum of HIP 57050 matches a small M-type main-sequence star, a red dwarf, with a stellar classification of M4.0V.[3] HIP 57050 has a metallicity twice that of the Sun and is among the highest in the immediate solar neighborhood.[7] It has a quiet chromosphere that displays little magnetic activity. A minimal level of amplitude variation from rotation suggests the star may be viewed from nearly pole-on.[8] This star has 36%[6] of the Sun's mass and 40% of the radius of the Sun. It is radiating just 1.5%[7] of the luminosity of the Sun from its photosphere at an effective temperature of 3,236 K.[5]