Delta1 Lyrae
| Observation data Epoch J2000.0 Equinox J2000.0 | ||
|---|---|---|
| Constellation | Lyra
| |
| Right ascension | 18h 53m 43.55924s[1] | |
| Declination | +36° 58′ 18.1891″[1] | |
| Apparent magnitude (V) | 5.56[2] | |
| Characteristics | ||
| Spectral type | B2.5V[3][4] | |
| U−B color index | −0.67[2] | |
| B−V color index | −0.15[2] | |
| Absolute magnitude (MV) | −1.55[6] | |
Semi-amplitude (K1)(primary) | 39.7±1.8 km/s | |
| Details | ||
| δ1 Lyr A | ||
Myr | ||
| Database references | ||
| SIMBAD | data | |
Delta1 Lyrae, its name
light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −26 km/s.[5] O. J. Eggen originally included this as a candidate member of the proposed Delta Lyrae cluster.[12]
The variable
The visible component of the pair has a blue-white hue with a
hydrogen fusion. It is a few million years old with a relatively high rotation rate and around 7–8 times the mass of the Sun. The star is radiating about 3,620[8] times the Sun's luminosity from its photosphere at an effective temperature of 20,350 K.[8]
There is a magnitude 9.93 visual companion at an
arcseconds along a position angle of 20°, as of 2012. This component was discovered by William Herschel.[15] It is an evolved giant star with a class of K2III at a distance of around 1,760 light years.[16]
References
- ^ .
- ^ doi:10.1086/129675.
- ^ S2CID 121565803.
- ^ S2CID 118629873.
- ^ Bibcode:1953GCRV..C......0W.
- ^ S2CID 119257644.
- ^ Bibcode:1958PDAO...10..407R. , p. 412
- ^ S2CID 111387483.
- ^ S2CID 119179065.
- ^ S2CID 18926523.
- ^ "del01 Lyr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-23.
{{cite web}}: CS1 maint: postscript (link) - .
- doi:10.1086/141124.
- Bibcode:1916PAllO...3..119J.
- doi:10.1086/323920.
- ^ "BD+36 3308". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-23.
{{cite web}}: CS1 maint: postscript (link)