19 Lyrae
Star in the constellation Lyra
From Wikipedia, the free encyclopedia
19 Lyrae is a single[10] variable star located approximately 950[2] light years away from the Sun in the northern constellation of Lyra.[9] It has the variable star designation V471 Lyr, while 19 Lyrae is the Flamsteed designation. This object is just bright enough to be visible to the naked eye, appearing as a dim, blue-white star with a baseline apparent visual magnitude of 5.93.[3] It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s, and may come as close as 167 light-years around 8.5 million years from now.[3]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lyra |
| Right ascension | 19h 11m 46.008s[2] |
| Declination | +31° 17′ 00.44″[2] |
| Apparent magnitude (V) | 5.93[3] |
| Characteristics | |
| Spectral type | B8 IIIp Si Sr[4] |
| B−V color index | −0.062±0.004[3] |
| Variable type | α2 CVn[5] |
| Astrometry | |
| Radial velocity (Rv) | −30.1±2.9[3] km/s |
| Proper motion (μ) | RA: −4.143 mas/yr[2] Dec.: −2.763 mas/yr[2] |
| Parallax (π) | 3.4213±0.0417 mas[2] |
| Distance | 950 ± 10 ly (292 ± 4 pc) |
| Absolute magnitude (MV) | −1.24[3] |
| Details | |
| Mass | 3.76±0.22[6] M☉ |
| Radius | 6.40[7] R☉ |
| Luminosity | 397.48[3] L☉ |
| Temperature | 11,194+501 −479[6] K |
| Rotational velocity (v sin i) | 35[8] km/s |
| Other designations | |
| 19 Lyr, V471 Lyr, NSV 11806, BD+31°3497, FK5 3532, GC 26459, HD 179527, HIP 94311, HR 7283, SAO 67946[9] | |
| Database references | |
| SIMBAD | data |
This is a magnetic chemically-peculiar star[11] with a stellar classification of B8 IIIp Si Sr,[4] showing abundance anomalies in silicon and strontium. The light variations of this star were discovered by J. E. Winzer in 1974.[12] It is an Alpha2 Canum Venaticorum-type variable with a period of 1.160898 days (or 7.0980 days[12]), ranging in magnitude from a high of 5.91 down to 5.98.[5] The surface magnetic field has a strength of (111.3±56.9)×10−4 T[13]
19 Lyrae has a moderate rotation rate, showing a projected rotational velocity of 35 km/s.[8] Stellar models give it an estimated 3.8[6] times the mass of the Sun and its girth is measured at 6.4[7] times the Sun's radius. It is radiating 397[3] times the luminosity of the Sun from its photosphere at an effective temperature of around 11,194 K.[6] The star has an absolute magnitude of −1.24,[3] which shows how bright the star would appear if it were located at a distance of 10 parsecs (33 ly) from the Sun.