Lambda Draconis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Draco |
| Right ascension | 11h 31m 24.22075s |
| Declination | +69° 19′ 51.8696″ |
| Apparent magnitude (V) | +3.85 |
| Characteristics | |
| Evolutionary stage | asymptotic giant branch |
| Spectral type | M0III-IIIa Ca1 |
| U−B color index | +1.97 |
| B−V color index | +1.62 |
| Variable type | slow irregular |
| Astrometry | |
| Radial velocity (Rv) | +6.58±0.30 km/s |
| Proper motion (μ) | RA: −40.97 mas/yr Dec.: −19.19 mas/yr |
| Parallax (π) | 9.79±0.15 mas |
| Distance | 333 ± 5 ly (102 ± 2 pc) |
| Absolute magnitude (MV) | −1.14±0.033 |
| Details | |
| Mass | 1.53±0.12 M☉ |
| Radius | 69.99+1.06 −1.10 R☉ |
| Luminosity | 884±52 L☉ |
| Surface gravity (log g) | 1.10±0.05 cgs |
| Temperature | 3,761±47 K |
| Metallicity [Fe/H] | 0.00 dex |
| Age | 2.33±0.48 Gyr |
| Other designations | |
| λ Dra, 1 Draconis, BD−70°665, FK5 433, HD 100029, HIP 56211, HR 4434, SAO 15532 | |
| Database references | |
| SIMBAD | data |
Lambda Draconis (λ Draconis, abbreviated Lam Dra, λ Dra), also named Giausar (/ˈdʒɔːzɑːr/ JAW-zar), is a solitary, orange-red star in the northern circumpolar constellation of Draco. It is visible to the naked eye with an apparent visual magnitude of +3.85. Based upon an annual parallax shift of 9.79 mas as seen from the Earth, the star is located around 333 light years from the Sun.
This is an evolved red giant star on the asymptotic giant branch with a stellar classification of M0III-IIIa Ca1. It is a suspected slow irregular variable with a periodicity of roughly 1,100 days. It has an estimated 1.53 times the mass of the Sun and a measured radius of 70 times the radius of the Sun. It is radiating 884 times the solar luminosity from its photosphere at an effective temperature of 3,761 K.