NGC 3603-A1
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Carina |
| Right ascension | 11h 15m 07.305s |
| Declination | −61° 15′ 38.43″ |
| Apparent magnitude (V) | 11.18 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | WN6h+WN6h |
| B−V color index | 1.03 |
| Variable type | EA |
| Astrometry | |
| Radial velocity (Rv) | −24.9±13.3 km/s |
| Proper motion (μ) | RA: +2.4 mas/yr Dec.: +2.8 mas/yr |
| Distance | 7,600 pc |
| Absolute magnitude (MV) | −7.3 |
| Orbit | |
| Primary | A1a |
| Name | A1b |
| Period (P) | 3.772980±00005 days |
| Eccentricity (e) | 0 (fixed) |
| Inclination (i) | 73.5±2.5° |
| Semi-amplitude (K1) (primary) | 307.9±19.6 km/s |
| Semi-amplitude (K2) (secondary) | 408.2±19.6 km/s |
| Details | |
| A1a | |
| Mass | 93.3±11.0 M☉ |
| Radius | 22.6 R☉ |
| Luminosity | 2,500,000 L☉ |
| Temperature | 37,000 K |
| Rotational velocity (v sin i) | 290±40 km/s |
| Age | 1.5 Myr |
| A1b | |
| Mass | 70.4±9.3 M☉ |
| Radius | 18.4 R☉ |
| Luminosity | 1,500,000 L☉ |
| Temperature | 42,000 K |
| Rotational velocity (v sin i) | 520±45 km/s |
| Age | 1.5 Myr |
| Other designations | |
| NGC 3603-A1, CD−60°3452A1, CPD−60°2732A1, HD 97950A1, HIP 54948A1, WR 43a, UCAC2 4794917, AAVSO 1110-60, NGC 3603 MDS 30 | |
| Database references | |
| SIMBAD | data |
NGC 3603-A1 (HD 97950A1) is a double-eclipsing binary star system located at the centre of the HD 97950 cluster in the NGC 3603 star-forming region, about 25,000 light years from Earth. Both stars are of spectral type WN6h and among the most luminous and most massive known.
HD 97950 was catalogued as a star, but was known to be a dense cluster or close multiple star. In 1926, the six brightest members were given letters from A to F, although several of them have since been resolved into more than one star. Star A was first resolved into three components using speckle interferometry, although they can now be directly imaged using space-based or adaptive optics. Component A1 was finally determined to be a spectroscopic binary.