| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 22m 03.43076s[1] |
| Declination | +24° 26′ 45.9526″[1] |
| Apparent magnitude (V) | 5.50[2] |
| Characteristics | |
| Spectral type | B6 IVe[3][4] |
| B−Vcolor index | −0.09±0.02[4] |
| Astrometry | |
| Radial velocity (Rv) | −11.0±3.6[5] km/s |
| Proper motion (μ) | RA: +0.605[1]mas/yr Dec.: −5.732[1]mas/yr |
| Parallax (π) | 2.7932±0.1493 mas[1] |
| Distance | 1,170 ± 60 ly (360 ± 20 pc) |
| Absolute magnitude (MV) | −1.88[4] |
| Details | |
| Mass | 7±1[6] M☉ |
| Radius | 11±1[6] R☉ |
| Luminosity (bolometric) | 1,345+215 −184[7] L☉ |
| Surface gravity (log g) | 3.52±0.21[7] cgs |
| Temperature | 13,170±330[7] K |
| Rotational velocity (v sin i) | 160±14[7] km/s |
| Other designations | |
| 25 Vul,BD+23°3986,HD 193911,HIP 100435,HR 7789,SAO 88580[8] | |
| Database references | |
| SIMBAD | data |
25 Vulpeculae is a single[2]star in the northernconstellation ofVulpecula, located roughly 1,170 light years away from the Sun. It is visible to the naked eye as a faint, blue-white hued star with anapparent visual magnitude of 5.50[2] This object is moving closer to the Earth with a heliocentricradial velocity of −11 km/s.[5]
This is aBe star with astellar classification of B6 IVe,[3] matching thespectrum of an agingsubgiant with a circumstellar disk of ionized gas. Cowley (1972) had it rated as a moreevolvedgiant star with a class of B8 IIIn,[9] where the 'n' notation indicates "nebulous"lines due to rapid rotation. It has a high rate of spin, showing aprojected rotational velocity of 160 km/s.[7] The star has 7 times themass of the Sun and 11 times theSun's radius.[6] It is radiating 1,345 times theluminosity of the Sun from itsphotosphere at aneffective temperature of 13,170 K.[7]
