HR 7703
| 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−B color index | +0.43[2] |
| B−V color 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) | 166.25 ± 0.27[1] mas |
| Distance | 19.62 ± 0.03 ly (6.015 ± 0.010 pc) |
| Absolute magnitude (MV) | 6.53[7] |
| Details | |
| HR 7703 A | |
| Mass | 0.65[8] M☉ |
| Radius | 0.66[8] R☉ |
| Luminosity | 0.26[8] L☉ |
| Surface gravity (log g) | 4.48 ± 0.17[8] cgs |
| Temperature | 5,075 ± 43[8] K |
| Metallicity [Fe/H] | –0.56 ± 0.04[8] dex |
| Rotational velocity (v sin i) | 1.8 ± 0.2[7] km/s |
| Age | 7.7[9] Gyr |
| HR 7703 B | |
| Mass | 0.24[10] M☉ |
| Radius | 0.28[3] R☉ |
| Other designations | |
| 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 (Gliese 783, 279 G. Sagittarii) is a binary star system in the constellation of Sagittarius. The brighter component has an apparent visual magnitude of 5.31,[2] which means it is visible from suburban skies at night. The two stars are separated by an angle of 7.10″, which corresponds to an estimated semimajor axis of 56.30 AU for their orbit.[10]
Based upon an annual parallax shift of 0.16625 arc seconds as measured by the Hipparcos satellite, this system is 19.62 light-years (6.015 parsecs) from Earth. It is approaching the Solar System at a velocity 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.[12]
This star system has been examined for an excess of radiation in the infrared, The presence of an infrared excess can be taken as an indication of a debris disk orbiting the star. However, no such excess was discovered around HR 7703.[13] 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.[14]
In popular culture
- In the Defiance TV series episode "Of a Demon in My View", the Omec ship Tsuroz was in this system in 1978 when they picked up a radio signal from Earth.
References
- 1 2 3 4 5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752
, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. - 1 2 3 4 Feinstein, A. (1966), "Photoelectric observations of Southern late-type stars", The Information Bulletin for the Southern Hemisphere, 8: 30, Bibcode:1966IBSH....8...30F.
- 1 2 Pasinetti-Fracassini, L. E.; et al. (February 2001), "Catalogue of Stellar Diameters (CADARS)", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- ↑ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637.
- ↑ Turnbull, M. C.; Tarter, J. C. (December 2003), "Target Selection for SETI. II. Tycho-2 Dwarfs, Old Open Clusters, and the Nearest 100 Stars", The Astrophysical Journal Supplement Series, 149 (2): 423–436, Bibcode:2003ApJS..149..423T, doi:10.1086/379320.
- 1 2 Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics, 418 (3): 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959.
- 1 2 Ammler-von Eiff, M.; Reiners, A. (June 2012), New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724.
- 1 2 3 4 5 6 Ghezzi, L.; et al. (September 2010), "Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity", The Astrophysical Journal, 720 (2): 1290–1302, arXiv:1007.2681, Bibcode:2010ApJ...720.1290G, doi:10.1088/0004-637X/720/2/1290.
- ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785.
- 1 2 Bonavita, M.; Desidera, S. (June 2007), "The frequency of planets in multiple systems", Astronomy and Astrophysics, 468 (2): 721–729, arXiv:astro-ph/0703754, Bibcode:2007A&A...468..721B, doi:10.1051/0004-6361:20066671.
- ↑ "LHS 486 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2014-01-10.
- ↑ Bobylev, Vadim V. (March 2010), "Searching for Stars Closely Encountering with the Solar System", Astronomy Letters, 36 (3): 220–226, arXiv:1003.2160, Bibcode:2010AstL...36..220B, doi:10.1134/S1063773710030060.
- ↑ Trilling, D. E.; et al. (February 2008), "Debris Disks around Sun-like Stars", The Astrophysical Journal, 674 (2): 1086–1105, arXiv:0710.5498, Bibcode:2008ApJ...674.1086T, doi:10.1086/525514.
- ↑ Wittenmyer, Robert A.; et al. (February 2011), On the Frequency of Jupiter Analogs, 727 (2), p. 102, arXiv:1011.4720, Bibcode:2011ApJ...727..102W, doi:10.1088/0004-637X/727/2/102.
External links
- Indus and Pavo
- "J. Herschel 5173 AB", SolStation, retrieved November 6, 2005