HD 139691
| Observation data Epoch Equinox J2000 |
|
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 15h 38m 12.91478s[1] |
| Declination | +36° 14′ 48.5597″ [1] |
| Apparent magnitude (V) | 6.9 (total) |
| Characteristics | |
| Spectral type | F4 V, F5 V, G4 V, F3V, F7V, unknown [2] |
| Astrometry | |
| Parallax (π) | 9.07 ± 5.48 mas |
| Distance | approx. 400 ly (approx. 110 pc) |
| Orbit | |
| Other designations | |
|
BD+36 2626, ADS 9731 AB, CCDM J15382+3615AB, WDS J15382+3615AB
|
|
| Database references | |
| SIMBAD | data |
HD 139691 is a star system that consists of six stars. Four of the stars are visually separate in the sky, forming a visual star system, which was resolved using adaptive optics in 1995.[3] Two of these stars were themselves found to be spectroscopic binaries in 1998, resulting in a total of six known stars in the system.[2]
The combined light from the whole system results in an integrated V magnitude of 6.9. The parallax measured by the Hipparcos satellite indicates that the system is relatively nearby at around 110 parsecs (360 light-years) from the Sun.[1] However, this distance is highly uncertain because the multiple stars in the system prevented Hipparcos from accurately measuring the parallax; the system may instead be at a distance of about 200 pc (650 ly).[4]
The star system has been considered as a possible target for direct imaging searches for exoplanets,[5] but no planets have yet been detected in the system.
References
- ^ a b c Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ a b Tokovinin, A. A.; Shatskii, N. I.; Magnitskii, A. K. (1998). "ADS 9731: A new sextuple system". Astronomy Letters 24: 795. Bibcode:1998PAZh...24..918T.
- ^ Drummond, Jack D.; Christou, Julian C.; Fugate, Robert Q. (1995). "Full Adaptive Optics Images of ADS 9731 and MU Cassiopeiae: Orbits and Masses". Astrophysical Journal 450: 380. Bibcode:1995ApJ...450..380D. doi:10.1086/176148.
- ^ Fabricius, C.; Makarov, V. V. (2000). "Hipparcos astrometry for 257 stars using Tycho-2 data". Astronomy and Astrophysics Supplement Series 144: 45. Bibcode:2000A&AS..144...45F. doi:10.1051/aas:2000198.
- ^ Janson, M. (2010). "The relevance of prior inclination determination for direct imaging of Earth-like planets". Monthly Notices of the Royal Astronomical Society 408: 514. arXiv:1006.2941. Bibcode:2010MNRAS.408..514J. doi:10.1111/j.1365-2966.2010.17135.x.
 |
This astronomy-related article is a stub. You can help Wikipedia by expanding it. |
