NR Vulpeculae
Star in the constellation Vulpecula
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NR Vulpeculae is a red supergiant or hypergiant[5] in the constellation Vulpecula. It is an irregular variable star with an apparent magnitude varying between 9.13 and 9.61, which is too faint to be seen to the naked eye.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 19h 50m 11.928s[2] |
| Declination | +24° 55′ 24.18″[2] |
| Apparent magnitude (V) | 9.13 - 9.61[3] |
| Characteristics | |
| Evolutionary stage | Red supergiant[4] or hypergiant[5] |
| Spectral type | M1Ia[3] or K3I[4] |
| Variable type | LC[3] |
| Astrometry | |
| Radial velocity (Rv) | 11.58±0.33[2] km/s |
| Proper motion (μ) | RA: −2.023±0.016 mas/yr[2] Dec.: −6.024±0.023 mas/yr[2] |
| Parallax (π) | 0.3225±0.0251 mas[2] |
| Distance | 8,844+711 −538 ly (2,713+218 −165 pc)[6] |
| Details | |
| Mass | 23[4][a] M☉ |
| Radius | 923+62 −50[7] R☉ |
| Luminosity | 197,000[8] L☉ |
| Surface gravity (log g) | −0.20[4] cgs |
| Temperature | 3,986[8] K |
| Metallicity [Fe/H] | +0.093[9] dex |
| Other designations | |
| NR Vulpeculae, TYC 2144-1244-1, GSC 02144-01244, IRC+20438, 2MASS J19501193+2455240, IRAS 19480+2447, AAVSO 1946+24, BD+24 3902, HD 339034, RAFGL 2462, UCAC2 40577951 | |
| Database references | |
| SIMBAD | data |
Characteristics
It has an spectral classification of M1Ia, meaning that it is a supergiant star of higher luminosity and spectral type M.[3] Levesque et al. (2005) published a different spectral type of K3I, meaning that it is a K-type supergiant star.[4] NR Vulpeculae has expanded to 920[7] times the Sun's size and is currently emitting 200,000 times its luminosity.[8] If placed in the Solar System, its photosphere would reach beyond Mars' orbit. It has a cool surface temperature of around 4,000 K,[8] giving it the typical orange color of a K-type star.[10]
NR Vulpeculae is also a slow irregular variable, with an apparent magnitude ranging from 9.13 to 9.61.[3]
It is considered a likely member of the Vulpecula OB1 stellar association.[4]
Notes
- Calculated using the star's absolute bolometric magnitude of −8.63 in the following equation:
log(M) = 0.50−0.1 • Mbol.
This results in a mass logarithm of 1.363, and 101.363 is equal to 23 solar masses.