38 Boötis
Star in the constellation Boötes / From Wikipedia, the free encyclopedia
38 Boötis is a single[8] star in the northern constellation of Boötes,[1] located approximately 157 light years from the Sun.[1] It has the traditional name Merga[9] /ˈmɜːrɡə/ and the Bayer designation h Boötis; 38 Boötis is the star's Flamsteed designation. This object is visible to the naked eye as a dim, yellow-white hued star with an apparent visual magnitude of 5.76.[2] It is moving closer to the Earth with a heliocentric radial velocity of −4.5 km/s.[2]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Boötes |
Right ascension | 14h 49m 18.67062s[1] |
Declination | +46° 06′ 58.3369″[1] |
Apparent magnitude (V) | 5.76[2] |
Characteristics | |
Evolutionary stage | subgiant[3] |
Spectral type | F6 IVs[4] |
B−V color index | 0.482±0.002[2] |
Astrometry | |
Radial velocity (Rv) | −4.5±0.2[2] km/s |
Proper motion (μ) | RA: –6.404[1] mas/yr Dec.: −78.073[1] mas/yr |
Parallax (π) | 20.7166 ± 0.0638 mas[1] |
Distance | 157.4 ± 0.5 ly (48.3 ± 0.1 pc) |
Absolute magnitude (MV) | 2.31[2] |
Details | |
Mass | 1.60±0.04[5] M☉ |
Radius | 2.51+0.04 −0.08[1] R☉ |
Luminosity | 9.511±0.039[1] L☉ |
Surface gravity (log g) | 3.92±0.02[5] cgs |
Temperature | 6,591±63[5] K |
Metallicity [Fe/H] | 0.11±0.05[5] dex |
Rotational velocity (v sin i) | 9.8[6] km/s |
Age | 1.74+0.19 −0.10[5] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
This is a sharp-lined ('s') subgiant[3] star with a stellar classification of F6 IVs,[4] which indicates it has consumed the hydrogen at its core and is evolving off the main sequence. It is about 1.7[5] billion years old and is spinning with a relatively low projected rotational velocity of 10 km/s,[6] as indicated by the sharp lines. The star has 1.6[5] times the mass of the Sun and 2.5[1] times the Sun's radius. It is radiating 9.5[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,591 K.[5]