| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h11m 43.33342s[1] |
| Declination | −23° 42′ 04.4346″[1] |
| Apparent magnitude (V) | 4.96[2] |
| Characteristics | |
| Spectral type | K0III[3] |
| U−B color index | +0.90[4] |
| B−V color index | +1.05[4] |
| Astrometry | |
| Radial velocity (Rv) | +5.71±0.20[1] km/s |
| Proper motion (μ) | RA: +9.337[1] mas/yr Dec.: −31.999[1] mas/yr |
| Parallax (π) | 12.6303 ± 0.2449 mas[1] |
| Distance | 258 ± 5 ly (79 ± 2 pc) |
| Absolute magnitude (MV) | 0.49[2] |
| Details | |
| Mass | 2.24[5] M☉ |
| Radius | 13.35+0.14 −0.92[1] R☉ |
| Luminosity | 78.6±1.7[1] L☉ |
| Surface gravity (log g) | 2.65[5] cgs |
| Temperature | 4,705+171 −25[1] K |
| Metallicity [Fe/H] | 0.00[5] dex |
| Rotational velocity (v sin i) | 1.6[6] km/s |
| Other designations | |
1 Sgr, CD–23°14047, GC 24799, HD 166464, HIP 89153, HR 6801, SAO 186437, CCDM J18117-2342A, WDS J18117-2342A[7] | |
| Database references | |
| SIMBAD | data |
HR 6801 is a single[8] star in the southern zodiac constellationofSagittarius. It was designated as 1 SagittariibyFlamsteed, but is now often referred to as 11 Sagittarii. Flamsteed's 11 Sgr actually refers to a different, much fainter star.[9] The object is orange in hue and is visible to the naked eye as a faint point of light with an apparent visual magnitude of 4.96.[2] The distance to this star is approximately 258 light years based on stellar parallax, and it is drifting further away with a radial velocity of +6 km/s.[1]
This is an aging giant star with a stellar classification of K0III.[10] It is a red clump giant,[11] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 2.24[5] times the mass of the Sun and has expanded to 13.4 times the Sun's radius. It is radiating 79 times the luminosity of the Sun from its photosphere at an effective temperature of 4,705 K.[1]
A faint visual companion, component B, has magnitude 11.51 and an angular separationof43.7″.[12]
