| | |
| Observation dataEpoch J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 19h 32m 21.6s |
| Declination | +69° 39' 40" |
| Apparent magnitude (V) | 4.68 |
| Characteristics | |
| Spectral type | K0 V |
| B-V Color index | 0.79 |
| U-B Color index | 0.38 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | 27.7 km/s |
| Proper motion (μ) | RA: 0.59843"/yr Dec.: -1.73881"/yr |
| Parallax (π) | 0.17359" ± 0.00041" |
| Distance | 18.78 ly (5.76 pc) |
| Absolute magnitude (MV) | 5.87 |
| Details | |
| Mass | 0.89 M☉ |
| RADIUS | 0.79 R☉ |
| Luminosity | 0.39 L☉ |
| Temperature | 5,100 K |
| Metallicity | 56-59% Sun |
| Rotation period | |
| Age | 3.3 × 109 years |
| Other designations | |
Sigma Draconis (σ Dra / σ Draconis) is a Star system 18.8 light years away from Earth. Its traditional name is Alsafi. It is in constellation Draco. Its visual magnitude is 4.68.
The star is an orange Main sequence dwarf of spectral type K0.
The traditional name "Alsafi" (also Athafi) supposedly derives from an Arabic word al-athafi "the cooking tripods".