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| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 16h 45m 06.3511s |
| Declination | +33° 30′ 33.226″ |
| Apparent magnitude (V) | 8.11 |
| Characteristics | |
| Spectral type | K7V[1] |
| U−B color index | 1.29 |
| B−V color index | 1.37 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | -29.6±0.9 km/s |
| Proper motion (μ) | RA: -39.18 mas/yr Dec.: 383.43 mas/yr |
| Parallax (π) | 101.59 ± 0.23 mas |
| Distance | 32.11 ± 0.07 ly (9.84 ± 0.02 pc) |
| Absolute magnitude (MV) | 8.11[2] |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gliese 638 is a main sequence star in the constellation of Hercules. It is located about 31.9 light years from the Earth. This is a suspected variable star with a measured apparent magnitude that ranges from 8.09–8.11.[3] As a K-class star, it has a lower mass than the Sun, and consequently is less luminous.
- ^ Wilson, O. C. (1962). "Relationship between colors and spectra of late main-sequence stars". Astrophysical Journal. 136: 793–799. Bibcode:1962ApJ...136..793W. doi:10.1086/147437.
- ^ Cite error: The named reference
Holmberg2009was invoked but never defined (see the help page). - ^ Kukarkin, B. V.; et al. (1981). Catalogue of suspected variable stars. Moscow, USSR: Academy of Sciences.