D Centauri
D Centauri is a double star in the southern constellation of Centaurus. The system is faintly visible to the naked eye as a point of light with a combined apparent magnitude of +5.31; the two components are of magnitude 5.78 and 6.98, respectively. It is located at a distance of approximately 610 light years from the Sun based on parallax, and is drifting further away with a radial velocity of ~10 km/s.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 12h 14m 02.697s |
| Declination | −45° 43′ 26.10″ |
| Apparent magnitude (V) | +5.31 (5.78 + 6.98) |
| Characteristics | |
| Spectral type | K3III (K4IIIab + K2IIIb) |
| U−B color index | +1.82/1.19 |
| B−V color index | +1.400±0.003/1.21 |
| Astrometry | |
| A | |
| Radial velocity (Rv) | +10.27±0.68 km/s |
| Proper motion (μ) | RA: −37.186 mas/yr Dec.: 6.606 mas/yr |
| Parallax (π) | 5.3350 ± 0.1399 mas |
| Distance | 610 ± 20 ly (187 ± 5 pc) |
| Absolute magnitude (MV) | −0.88 |
| B | |
| Proper motion (μ) | RA: −33.604 mas/yr Dec.: 5.434 mas/yr |
| Parallax (π) | 4.9297 ± 0.0550 mas |
| Distance | 662 ± 7 ly (203 ± 2 pc) |
| Details | |
| A | |
| Radius | 42.8+1.1 −2.13 R☉ |
| Luminosity | 434±13 L☉ |
| Temperature | 4,026+104 −50 K |
| B | |
| Radius | 13.5+1.7 −1.9 R☉ |
| Luminosity | 90.5±1.4 L☉ |
| Temperature | 4,853+275 −392 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The dual nature of this star was announced by C. Rumker in 1837. As of 2015, the pair had an angular separation of 2.70″ along a position angle of 242°. This orange-hued double has a combined stellar classification of K3III, matching an aging giant star that has exhausted the supply of hydrogen at its core. In 1984, C. J. Corbally found a class of K4IIIab for the primary and K2IIIb for the fainter secondary.