QU Normae
Star in the constellation Norma
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QU Normae, also known as HR 6131, is a blue supergiant star in the constellation Norma. It is also a variable star, thought to be an α Cyg variable.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Norma |
| Right ascension | 16h 29m 42.32777s[1] |
| Declination | −46° 14′ 35.6309″[1] |
| Apparent magnitude (V) | 5.37[2] (5.27 - 5.41[3]) |
| Characteristics | |
| Spectral type | B1.5 Iap[4] |
| U−B color index | −0.44[2] |
| B−V color index | +0.62[2] |
| Variable type | α Cyg[3] |
| Astrometry | |
| Radial velocity (Rv) | −14.80 ± 3.2[5] km/s |
| Proper motion (μ) | RA: −3.403 mas/yr[1] Dec.: −4.151 mas/yr[1] |
| Parallax (π) | 0.6505±0.0794 mas[1] |
| Distance | approx. 5,000 ly (approx. 1,500 pc) |
| Absolute magnitude (MV) | −7.50[6] |
| Details | |
| Mass | 43[7] M☉ |
| Radius | 110[7][a] R☉ |
| Luminosity | 417,000[6] L☉ |
| Surface gravity (log g) | 2.00[7] cgs |
| Temperature | 17,000[7] K |
| Rotational velocity (v sin i) | 44[7] km/s |
| Other designations | |
| QU Normae, HD 148379, HIP 80782, HR 6131, CD−45°10697 | |
| Database references | |
| SIMBAD | data |
The apparent magnitude of QU Normae varies somewhat irregularly between 5.27 and 5.41. The General Catalogue of Variable Stars quotes a period of 4.818 days,[3] but other research only shows likely periods longer than 10 days.[8]
QU Normae has a spectral type B1.5 Ia, a luminous supergiant that has swollen and cooled off the main sequence. Surface abundances suggest that it has not yet passed through a red supergiant phase.[6] Around 5,000 light-years distant, it shines with a luminosity approximately 417,000 times that of the Sun and has a diameter around 110 times that of the Sun.
Notes
- Calculated using surface gravity and mass, via the equation log(R/R☉) = 2.22 + 0.5 • log(M/M☉) − 0.5 • log(g).