38 Boötis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 49m 18.67062s |
| Declination | +46° 06′ 58.3369″ |
| Apparent magnitude (V) | 5.76 |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | F6 IVs |
| B−V color index | 0.482±0.002 |
| Astrometry | |
| Radial velocity (Rv) | −4.5±0.2 km/s |
| Proper motion (μ) | RA: –6.404 mas/yr Dec.: −78.073 mas/yr |
| Parallax (π) | 20.7166±0.0638 mas |
| Distance | 157.4 ± 0.5 ly (48.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.31 |
| Details | |
| Mass | 1.60±0.04 M☉ |
| Radius | 2.51+0.04 −0.08 R☉ |
| Luminosity | 9.511±0.039 L☉ |
| Surface gravity (log g) | 3.92±0.02 cgs |
| Temperature | 6,591±63 K |
| Metallicity [Fe/H] | 0.11±0.05 dex |
| Rotational velocity (v sin i) | 9.8 km/s |
| Age | 1.74+0.19 −0.10 Gyr |
| Other designations | |
| Merga, Marrha, El Mara el Musalsela, Falx Italica, h Boötis, 38 Boo, BD+46°1993, FK5 1383, GC 19959, HD 130945, HIP 72487, HR 5533, SAO 45226 | |
| Database references | |
| SIMBAD | data |
38 Boötis is a single star in the northern constellation of Boötes, located approximately 157 light years from the Sun. It has the traditional name Merga /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. It is moving closer to the Earth with a heliocentric radial velocity of −4.5 km/s.
This is a sharp-lined ('s') subgiant star with a stellar classification of F6 IVs, which indicates it has consumed the hydrogen at its core and is evolving off the main sequence. It is about 1.7 billion years old and is spinning with a relatively low projected rotational velocity of 10 km/s, as indicated by the sharp lines. The star has 1.6 times the mass of the Sun and 2.5 times the Sun's radius. It is radiating 9.5 times the luminosity of the Sun from its photosphere at an effective temperature of 6,591 K.