QV Normae
Star in the constellation Norma
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QV Normae, also known as Norma X-2, is a high mass X-ray binary star system in the constellation Norma. It varies between apparent magnitudes of 16.19 and 16.31.[2]
| Observation data Epoch J2000.0 ICRS Equinox J2000.0 ICRS | |
|---|---|
| Constellation | Norma |
| Right ascension | 15h 42m 23.36s[1] |
| Declination | −52° 23′ 09.6″ [1] |
| Apparent magnitude (V) | 16.19 - 16.31 [2] |
| Characteristics | |
| Spectral type | B0Iabe[2] |
| Other designations | |
| Norma X-2 | |
| Database references | |
| SIMBAD | data |
The X-ray source was first identified in the early 1970s.[3] The nature of the system was discovered in 1978 by astronomers who aligned a visual source of a reddened hot blue-white star with the X-ray source 4U 1538 - 52. The components are a blue-white supergiant estimated to have a mass around 20 times that of the Sun and a neutron star initially estimated at around 1.4 solar masses,[4] later revised to 0.8 solar masses. The stellar wind from the more massive star is drawn to the magnetic poles of neutron star, forming an accretion column and producing X-rays. The system has been estimated to lie anywhere from 4500 to 6500 parsecs (15,000-20,000 light-years) from Earth.[3]