27 Vulpeculae
Star in the constellation Vulpecula
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27 Vulpeculae is a single,[10] blue-white star in the northern constellation of Vulpecula. It is a dim star, visible to the naked eye, with an apparent visual magnitude of 5.59.[2] An annual parallax shift of 10.6692±0.0483 mas[1] provides a distance estimate of about 306 light-years. It is moving closer with a heliocentric radial velocity of −22 km/s,[6] and will make perihelion passage at a distance of around 119 ly (36.56 pc) in 3.75 million years.[5]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 37m 04.6724s[1] |
| Declination | +26° 27′ 43.006″[1] |
| Apparent magnitude (V) | 5.590[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1][3] |
| Spectral type | B9 V[4][3] |
| B−V color index | −0.050±0.004[5] |
| Astrometry | |
| Radial velocity (Rv) | −21.8±4.3[6] km/s |
| Proper motion (μ) | RA: 15.349±0.042[1] mas/yr Dec.: −11.775±0.040[1] mas/yr |
| Parallax (π) | 10.6692±0.0483 mas[1] |
| Distance | 306 ± 1 ly (93.7 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.65[5] |
| Details | |
| Mass | 2.77±0.03[3] M☉ |
| Radius | 3.1[7] R☉ |
| Luminosity | 75.0+4.8 −4.5[3] L☉ |
| Surface gravity (log g) | 3.781[8] cgs |
| Temperature | 10,789+50 −49[3] K |
| Metallicity [Fe/H] | −0.27±0.04[5] dex |
| Rotational velocity (v sin i) | 335[3] km/s |
| Other designations | |
| 27 Vul, BD+25° 4302, FK5 3649, HD 196504, HIP 101716, HR 7880, SAO 88903[9] | |
| Database references | |
| SIMBAD | data |
This is a B-type main-sequence star with a stellar classification of B9 V.[4] It is spinning rapidly, showing a projected rotational velocity of 335.[3] The star has an estimated 2.77[3] times the mass of the Sun and about 3.1[7] times the Sun's radius. It is radiating 75[3] times the Sun's luminosity from its photosphere at an effective temperature of 10,789 K.[3]
BD Vulpeculae
The location of the reddish colored carbon star BD Vulpeculae (CCCS 2916 / CGCS 4915) is, as seen from Earth, immediately northeast of 27 Vulpeculae. Astronomers and amateur astronomers could use 27 Vulpeculae as guidestar to try to find BD Vulpeculae and to see the color contrast of the bluish white star 27 Vulpeculae and the nearby reddish carbon star.