| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 20h 11m 11.93827s[1] |
| Declination | –36° 06′ 04.3610″[1] |
| Apparent magnitude (V) | 5.31[2]/11.50[3] |
| Characteristics | |
| Spectral type | K2.5 V[4] + M4 V[5] |
| U−Bcolor index | +0.43[2] |
| B−Vcolor index | +0.85[2] |
| Astrometry | |
| Radial velocity (Rv) | –129.4[6] km/s |
| Proper motion (μ) | RA: +456.99[1]mas/yr Dec.: –1574.64[1]mas/yr |
| Parallax (π) | 166.3272±0.1065 mas[7] |
| Distance | 19.61 ± 0.01 ly (6.012 ± 0.004 pc) |
| Absolute magnitude (MV) | 6.53[8] |
| Details | |
| HR 7703 A | |
| Mass | 0.65[9] M☉ |
| Radius | 0.66[9] R☉ |
| Luminosity | 0.26[9] L☉ |
| Surface gravity (log g) | 4.48 ± 0.17[9] cgs |
| Temperature | 5,075 ± 43[9] K |
| Metallicity [Fe/H] | –0.56 ± 0.04[9] dex |
| Rotational velocity (v sin i) | 1.8 ± 0.2[8] km/s |
| Age | 7.7[10] Gyr |
| HR 7703 B | |
| Mass | 0.24[11] M☉ |
| Radius | 0.28[3] R☉ |
| Other designations | |
| 279G. Sagittarii, Gliese 783,CD –36°13940,GCTP 4782.00,HD 191408,HIP 99461,SAO 211885.[12] | |
| HR 7703 A:LHS 486,LFT 1529,LTT 7988 | |
| HR 7703 B: LHS 487, LFT 1530, LTT 7989 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
  HR 7703 Location of HR 7703 in the constellationSagittarius | |
HR 7703 (Gliese 783, 279 G. Sagittarii) is abinary star system in theconstellation ofSagittarius. The brighter component has anapparent visual magnitude of 5.31,[2] which means it isvisible from suburban skies at night. The two stars are separated by an angle of 7.10″, which corresponds to an estimatedsemimajor axis of 56.30 AU for their orbit.[11]
Based upon an annualparallax shift of 0.16625 arc seconds as measured by theHipparcos satellite, this system is 19.62light-years (6.015parsecs) fromEarth. It is approaching theSolar System at avelocity of approximately 129 kilometers per second.[6] At this rate, it will make its closest approach in 41,100 years when it comes to within 6.7 light-years (2.05 parsecs) of the Sun.[13]
This star system has been examined for anexcess of radiation in theinfrared. The presence of an infrared excess can be taken as an indication of adebris disk orbiting the star. However, no such excess was discovered around HR 7703.[14]Radial velocity data collected over a period of 12 years was examined for signs of periodicity caused by a planet orbiting at a distance of 3–6 AU, but none was detected.[15] A slight linear trend in the radial velocities of the primary is probably due to the companion star.[16]
