HD 190007
HD 190007, also known as Gliese 775, is a star with a close orbiting exoplanet in the constellation of Aquila. Parallax measurements by Gaia put the star at a distance of 41.5 light-years (12.7 parsecs) away from the Sun. It is drifting closer with a radial velocity of −30.3 km/s, and is predicted to come within 11.8 light-years in 375,000 years. The star has an absolute magnitude of 6.91, but at its present distance the apparent visual magnitude is 7.46, which is too faint to be viewed with the naked eye.
Four representative light curves for HD 190007, adapted from Burt et al. (2020) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 20h 02m 47.04569s |
| Declination | +03° 19′ 34.2658″ |
| Apparent magnitude (V) | 7.46 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | K5 V |
| U−B color index | +1.09 |
| B−V color index | +1.11 |
| Variable type | BY Dra |
| Astrometry | |
| Radial velocity (Rv) | −30.268±0.0013 km/s |
| Proper motion (μ) | RA: −90.383 mas/yr Dec.: 119.430 mas/yr |
| Parallax (π) | 78.6465 ± 0.0198 mas |
| Distance | 41.47 ± 0.01 ly (12.715 ± 0.003 pc) |
| Absolute magnitude (MV) | 6.91 |
| Details | |
| Mass | 0.77±0.02 M☉ |
| Radius | 0.80 R☉ |
| Luminosity | 0.24 L☉ |
| Surface gravity (log g) | 4.50 cgs |
| Temperature | 4,610±20 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotation | 28.626±0.046 d |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
The spectrum of HD 190007 matches a K-type main-sequence star with a stellar classification of K5 V. It is classified as a BY Draconis variable, showing a moderate level of magnetic activity in its chromosphere with a suspected activity cycle lasting 13.7 years. The star displays a mild enhancement of metals and its age is uncertain. It has 77% of the mass of the Sun, 80% of the Sun's radius, and is spinning with a rotation period of 28.6 days. HD 190007 is radiating 24% of the luminosity of the Sun from its photosphere at an effective temperature of 4,610 K.