| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 55m 52.322s [1] |
| Declination | −59° 22′ 16.45″ [1] |
| Apparent magnitude (V) | 7.86 [2] |
| Characteristics | |
| Spectral type | B1 Ib [3] |
| Apparent magnitude (U) | 7.34 |
| Apparent magnitude (B) | 8.00 |
| Apparent magnitude (V) | 7.86 |
| Apparent magnitude (R) | 8.88 |
| Apparent magnitude (G) | 7.7591 |
| Apparent magnitude (J) | 7.428 |
| Apparent magnitude (H) | 7.426 |
| Apparent magnitude (K) | 7.385 |
| Astrometry | |
| Proper motion (μ) | RA: −3.376 [1] mas/yr Dec.: −1.300 [1] mas/yr |
| Parallax (π) | 0.5846±0.0260 mas [1] |
| Distance | 5,600 ± 200 ly (1,710 ± 80 pc) |
| Absolute magnitude (MV) | −5.32 [4] |
| Details | |
| Mass | 7.0 [5] M☉ |
| Radius | 19.6 [6] R☉ |
| Luminosity | 4,124 [7] L☉ |
| Surface gravity (log g) | 2.14 [7] cgs |
| Temperature | 26,424 [8] K |
| Age | 31.6 [5] Myr |
| Other designations | |
| CD−58°5362, HIP 68034, SAO 241302 | |
| Database references | |
| SIMBAD | data |
HD 121228 is a blue supergiant star located in the constellation Centaurus. The star is noted for its close visual proximity to the planetary nebula SuWt 2. [9]