HD 3240
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 36m 08.31020s |
| Declination | +54° 10′ 06.4197″ |
| Apparent magnitude (V) | 5.08 |
| Characteristics | |
| Spectral type | B7 III |
| B−V color index | −0.098±0.003 |
| Variable type | constant |
| Astrometry | |
| Radial velocity (Rv) | +1.1±2.8 km/s |
| Proper motion (μ) | RA: +22.954 mas/yr Dec.: −1.905 mas/yr |
| Parallax (π) | 6.6398±0.0816 mas |
| Distance | 491 ± 6 ly (151 ± 2 pc) |
| Absolute magnitude (MV) | −1.03 |
| Details | |
| Mass | 3.91±0.08 M☉ |
| Radius | 3.9 R☉ |
| Luminosity | 405+43 −39 L☉ |
| Surface gravity (log g) | 3.696±0.016 cgs |
| Temperature | 11885±82 K |
| Metallicity [Fe/H] | −0.59 dex |
| Rotational velocity (v sin i) | 59 km/s |
| Age | 201 Myr |
| Other designations | |
| BD+53°102, GC 708, HD 3240, HIP 2854, HR 144, SAO 21551, GSC 03654-02131 | |
| Database references | |
| SIMBAD | data |
HD 3240 is a single star in the northern constellation of Cassiopeia, positioned near Zeta Cassiopeiae. This object has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.08. The distance to HD 3240 is approximately 480 light years based on parallax. At that range, the visual magnitude of the star is diminished by an extinction of 0.22 due to interstellar dust.
This star has a stellar classification of B7 III, matching an aging giant star that has exhausted the supply of hydrogen at its core. It is around 201 million years old and is spinning with a projected rotational velocity of 59 km/s, well below its critical velocity of 335 km/s. The star has 3.9 times the mass of the Sun and is radiating 405 times the Sun's luminosity from its photosphere at an effective temperature of 11,885 K.