NW Puppis
B-type star in the constellation Puppis
From Wikipedia, the free encyclopedia
NW Puppis, also known as υ2 Puppis, is a star in the constellation Puppis. Located around 910 light-years distant, it shines with a luminosity approximately 2,000 times that of the Sun and has a surface temperature of 17,930 K.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Puppis |
| Right ascension | 07h 18m 38.18632s[2] |
| Declination | −36° 44′ 33.8557″[2] |
| Apparent magnitude (V) | 5.11[3] |
| Characteristics | |
| Spectral type | B3 Vne[4] |
| Variable type | β Cep[3] |
| Astrometry | |
| Radial velocity (Rv) | +18.00±10[5] km/s |
| Proper motion (μ) | RA: −10.848[2] mas/yr Dec.: +6.699[2] mas/yr |
| Parallax (π) | 3.5875±0.1683 mas[2] |
| Distance | 910 ± 40 ly (280 ± 10 pc) |
| Details | |
| Mass | 6.5[6] M☉ |
| Radius | 5.6[6] R☉ |
| Luminosity | 1,995[6] L☉ |
| Surface gravity (log g) | 4.07±0.57[7] cgs |
| Temperature | 17,930±540[7] K |
| Rotation | 1.42 days[8] |
| Rotational velocity (v sin i) | 80±8[7] km/s |
| Age | 40[6] Myr |
| Other designations | |
| υ2 Pup, NW Pup, CD−36°3519, HD 57219, HIP 35406, HR 2790, SAO 197837, NW Puppis, υ2 Puppis, Upsilon2 Puppis, Upsilon2 Pup | |
| Database references | |
| SIMBAD | data |
The star's variability was first detected in 1970 (based on observations made at La Silla Observatory), and announced by Armand van Hoof in 1973.[9] It was given its variable star designation in 1977.[10] Anamarija Stankov ruled this star out as a Beta Cephei variable,[11] but the GCVS and the International Variable Star Index classify it as both a Beta Cephei variable and a rotating ellipsoidal variable.[12][13] The GCVS lists its period as 0.125 days, but the TESS data shows lower frequency and stochastic brightness variations.[12][14]
Neither component of this double is given a letter in Lacaille's catalogue or the British Association star catalogue.[15][16] Gould gave them the designations (Latin letter) v1 and v2 Puppis, but these are rarely used.[17] Lacaille applied the Greek letter υ to the star now called υ Carinae.[15] The designation υ2 first appeared in several catalogues at the end of the 19th century.[18]