24 Ursae Majoris
24 Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, located 101.5 light-years from the Sun. It has the variable star designation DK Ursae Majoris and the Bayer designation d Ursae Majoris; 24 Ursae Majoris is the Flamsteed designation. This object is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 4.54. It is moving closer to the Earth with a heliocentric radial velocity of −27 km/s, and is expected to come as close as 51 light-years in around 879,000 years.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 09h 34m 28.86175s |
| Declination | +69° 49′ 49.2265″ |
| Apparent magnitude (V) | 4.54 |
| Characteristics | |
| Spectral type | G4 III-IV |
| B−V color index | 0.781±0.011 |
| Variable type | RS CVn |
| Astrometry | |
| Radial velocity (Rv) | −27.0±0.2 km/s |
| Proper motion (μ) | RA: −64.785 mas/yr Dec.: +77.214 mas/yr |
| Parallax (π) | 30.9269 ± 0.1621 mas |
| Distance | 105.5 ± 0.6 ly (32.3 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.16±0.013 |
| Details | |
| Mass | 1.9 M☉ |
| Radius | 4.6 R☉ |
| Luminosity | 14.9 L☉ |
| Surface gravity (log g) | 3.44 cgs |
| Temperature | 5,335 K |
| Metallicity [Fe/H] | −0.19 dex |
| Rotation | 10 d |
| Rotational velocity (v sin i) | 5.5 km/s |
| Age | 1.0±0.1 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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