HD 166
A light curve for V439 Andromedae, plotted from TESS data, with the 6.23 day rotation period shown in red, | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 06m 36.7841s |
| Declination | +29° 01′ 17.4103″ |
| Apparent magnitude (V) | 6.13 – 6.17 |
| Characteristics | |
| Spectral type | K0Ve |
| U−B color index | +0.30 |
| B−V color index | +0.755 |
| Variable type | BY Dra |
| Astrometry | |
| Radial velocity (Rv) | −6.9±0.2 km/s |
| Proper motion (μ) | RA: 380.092±0.060 mas/yr Dec.: −177.573±0.037 mas/yr |
| Parallax (π) | 72.5764±0.0498 mas |
| Distance | 44.94 ± 0.03 ly (13.779 ± 0.009 pc) |
| Absolute magnitude (MV) | 5.41 |
| Details | |
| Mass | 0.889 M☉ |
| Radius | 0.9172±0.0090 R☉ |
| Luminosity | 0.6078±0.0099 L☉ |
| Surface gravity (log g) | 4.49±0.09 cgs |
| Temperature | 5509±34 K |
| Metallicity [Fe/H] | 0.00±0.03 dex |
| Rotation | 6.23±0.01 days |
| Rotational velocity (v sin i) | 4.1 km/s |
| Age | 78±28 Myr |
| Other designations | |
| BD+28°4704, GC 95, GSC 01735-02532, GSC 01735-00927, Gliese 5, HD 166, HIP 544, HR 8, SAO 73743, PPM 89410, NSV 33, V439 Andromedae | |
| Database references | |
| SIMBAD | data |
HD 166 or V439 Andromedae (ADS 69 A) is a 6th magnitude star in the constellation Andromeda, approximately 45 light years away from Earth. It is a variable star of the BY Draconis type, varying between magnitudes 6.13 and 6.18 with a 6.23 days periodicity. It appears within one degree of the star Alpha Andromedae and is a member of the Hercules-Lyra association moving group. It also happens to be less than 2 degrees from right ascension 00h 00m.