1 Lacertae
Star in the constellation Lacerta
From Wikipedia, the free encyclopedia
1 Lacertae is a solitary[10] star in the northern constellation of Lacerta. It is visible to the naked eye with an apparent visual magnitude of 4.15. Based upon measurements by the Hipparcos spacecraft, this star is located at a distance of roughly 680 light years. It is moving closer to the Earth with a heliocentric radial velocity of −8.6 km/s.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lacerta |
| Right ascension | 22h 15m 58.17690s[1] |
| Declination | +37° 44′ 55.4468″[1] |
| Apparent magnitude (V) | 4.15[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K3 II-III[4] |
| U−B color index | +1.70[2] |
| B−V color index | +1.43[2] |
| Astrometry | |
| Radial velocity (Rv) | −8.58[5] km/s |
| Proper motion (μ) | RA: +8.851[1] mas/yr Dec.: –0.089[1] mas/yr |
| Parallax (π) | 4.8108±0.1322 mas[1] |
| Distance | 680 ± 20 ly (208 ± 6 pc) |
| Absolute magnitude (MV) | −2.61+0.27 −0.24[6] |
| Details[7] | |
| Mass | 4.16±0.28 M☉ |
| Radius | 69.01+3.32 −3.07 R☉ |
| Luminosity | 1,453±147 L☉ |
| Surface gravity (log g) | 2.15 cgs |
| Temperature | 4,288±62 K |
| Metallicity [Fe/H] | −0.01 dex |
| Rotational velocity (v sin i) | 10[8] km/s |
| Age | 170±30 Myr |
| Other designations | |
| 1 Lac, NSV 25864, BD+37°4526, HD 211388, HIP 109937, HR 8498, SAO 72191[9] | |
| Database references | |
| SIMBAD | data |
A stellar classification of K3 II-III[4] suggests this is an evolved star with a luminosity class intermediate between a giant and bright giant. It is 170 million years old with around four times the mass of the Sun and has expanded to an estimated 69 times the Sun's radius. The star is radiating 1,453 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,288 K, giving it the orange-hued glow of a K-type star.[11] The star was once a suspected variable, but this was later rescinded.[12]