HIP 57274
From Wikipedia, the free encyclopedia
HIP 57274 is a star in the northern circumpolar constellation of Ursa Major with a system of three planets.[2] It is invisible to the naked eye, having an apparent visual magnitude of 8.96.[2] The distance to this system is 84.4 light years based on stellar parallax, and it is drifting further away with a radial velocity of +30 km/s.[1] The star has a relatively high rate of proper motion, traversing the celestial sphere at the rate of 0.382 arcsecond/year.[6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ursa Major |
Right ascension | 11h 44m 40.9643s[1] |
Declination | +30° 57′ 33.4509″[1] |
Apparent magnitude (V) | 8.96[2] |
Characteristics | |
Spectral type | K5 V[2] |
U−B color index | +1.06[3] |
B−V color index | +1.111±0.016[4] |
Astrometry | |
Radial velocity (Rv) | +29.76±0.35[1] km/s |
Proper motion (μ) | RA: −27.069±0.081[1] mas/yr Dec.: −381.708±0.079[1] mas/yr |
Parallax (π) | 38.6381 ± 0.0499 mas[1] |
Distance | 84.4 ± 0.1 ly (25.88 ± 0.03 pc) |
Absolute magnitude (MV) | 6.89[2] |
Details[2] | |
Mass | 0.73±0.05 M☉ |
Radius | 0.68±0.03 R☉ |
Luminosity | 0.19±0.01 L☉ |
Surface gravity (log g) | 4.71±0.1 cgs |
Temperature | 4,640±100 K |
Metallicity [Fe/H] | +0.09±0.05 dex |
Rotation | 45 d |
Rotational velocity (v sin i) | 0.5±0.5 km/s |
Age | 7.87±5 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
This is an ordinary K-type main-sequence star with a stellar classification of K5V.[2] It appears to be older than the Sun with an age of roughly eight billion years and is spinning slowly with a projected rotational velocity of under 1 km/s. The star has 73% of the mass of the Sun and 68% of the Sun's radius. The abundance of elements heavier than helium is about the same or slightly higher than in the Sun. The star is radiating just 19% of the luminosity of the Sun from its photosphere at an effective temperature of 4,640 K.