HD 93403
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 45m 44.11931s |
| Declination | −59° 24′ 28.1431″ |
| Apparent magnitude (V) | 7.272 |
| Characteristics | |
| Spectral type | O5.5III(fc)var (O5.5I + O7V) |
| U−B color index | −0.747 |
| B−V color index | +0.212 |
| Astrometry | |
| Radial velocity (Rv) | 14.80 km/s |
| Proper motion (μ) | RA: -7.27 mas/yr Dec.: 2.45 mas/yr |
| Parallax (π) | 1.22±0.45 mas |
| Distance | 3,200 pc |
| Orbit | |
| Period (P) | 15.093 days |
| Semi-major axis (a) | 121 R☉ |
| Eccentricity (e) | 0.234 |
| Inclination (i) | ~31° |
| Semi-amplitude (K1) (primary) | 79.3 km/s |
| Semi-amplitude (K2) (secondary) | 139.0 km/s |
| Details | |
| Primary | |
| Mass | 68.5 M☉ |
| Radius | 24 R☉ |
| Luminosity | 1,050,000 L☉ |
| Temperature | 39,300 K |
| Secondary | |
| Mass | 37.3 M☉ |
| Radius | 10 R☉ |
| Luminosity | 257,000 L☉ |
| Temperature | 40,100 K |
| Other designations | |
| HD 93403, HIP 52628, CD−58°3545, 2MASS J10454411-5924281, GSC 08626-00641, TYC 8626-641-1 | |
| Database references | |
| SIMBAD | data |
HD 93403 is a spectroscopic binary containing two highly luminous hot blue stars. It is 10,000 light years away in the Carina Nebula in the constellation Carina. It appears to have spectral type O5.5III, but this is composed of two spectra from a blue supergiant and blue main sequence star of spectral type O5.5I and O7V respectively. The two stars orbit every 15 days with a separation that varies from 93 R☉ to 149 R☉. The binary is shedding mass at the high rate of 0.0005 M☉ per year.
HD 93403 exhibits the Struve-Sahade effect, where the strength of the spectral lines of the individual components varies during the orbit. It also has colliding stellar winds that produce variable x-ray and non-thermal radio emission.