  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia [1] |
| Right ascension | 00h 04m 13.6625s [2] |
| Declination | +62° 17′ 15.591″ [2] |
| Apparent magnitude (V) | +5.884 [3] |
| Characteristics | |
| Spectral type | A1II-III [4] |
| U−B color index | +0.29 [5] |
| B−V color index | +0.30 [5] |
| Astrometry | |
| Radial velocity (Rv) | −23.43±0.16 [2] km/s |
| Proper motion (μ) | RA: −0.936 [2] mas/yr Dec.: −0.263 [2] mas/yr |
| Parallax (π) | 1.3781±0.0237 mas [2] |
| Distance | 2,370 ± 40 ly (730 ± 10 pc) |
| Details | |
| Mass | 5.1 [6] M☉ |
| Radius | 26 [7] R☉ |
| Luminosity | 2,208 [7] L☉ |
| Surface gravity (log g) | 2.08 [6] cgs |
| Temperature | 7,719 [7] K |
| Metallicity [Fe/H] | −0.32 [6] dex |
| Rotational velocity (v sin i) | 33 [8] km/s |
| Age | 25.1 [9] Myr |
| Other designations | |
| 9 Cas, HR 9100, HD 225180, BD+61°2586, HIP 330 | |
| Database references | |
| SIMBAD | data |
9 Cassiopeiae (9 Cas) is a white giant star in the constellation Cassiopeia, about 2,370 light years away.
9 Cassiopeiae is classified as an A1 type giant or bright giant. One study noted peculiarities in the spectrum that could indicate a λ Boötis star, [10] but other researchers have refuted this. [11] [8]
At an age of 25 million years, 9 Cassiopeiae has expanded away from the main sequence after exhausting its core hydrogen and now has a radius about 26 times that of the Sun. With an effective temperature of about 7,700 K , it emits more than two thousand times the luminosity of the Sun.
9 Cassiopeiae has a number of faint companions listed in multiple star catalogues, [12] but they all appear to be at different distances [13] and none are thought to be gravitationally associated. [14]
