QS Virginis (abbreviated QS Vir) is an eclipsing binary system approximately 163 light-years away from the Sun,[1][2] forming a cataclysmic variable. The system comprises an eclipsing white dwarf and red dwarf that orbit each other every 3.37 hours.[1]
 Visual band light curves for QS Virginis, adapted from O’Donoghue et al. (2003).[1] The lowest plot shows two pre-eclipse dips. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 13h 49m 52.0032s[2] |
| Declination | −13° 13′ 37.0019″[2] |
| Apparent magnitude (V) | +14.8 |
| Characteristics | |
| Spectral type | DAm / M3.5V |
| Astrometry | |
| Proper motion (μ) | RA: 41.618±0.108[2] mas/yr Dec.: 17.984±0.097[2] mas/yr |
| Parallax (π) | 19.9632 ± 0.0584 mas[2] |
| Distance | 163.4 ± 0.5 ly (50.1 ± 0.1 pc) |
| Absolute magnitude (MV) | 11.74 + 11.82[1] |
| Orbit | |
| Period (P) | 217.092 min[1] |
| Semi-major axis (a) | 0.0056 AU |
| Eccentricity (e) | 0.0 |
| Inclination (i) | 60[1]° |
| Details[1] | |
| White dwarf | |
| Mass | 0.78 M☉ |
| Radius | 0.011 R☉ |
| Luminosity | 0.0044[3] L☉ |
| Surface gravity (log g) | 8.34 cgs |
| Temperature | 14,200 K |
| Rotational velocity (v sin i) | 400 km/s |
| Red dwarf | |
| Mass | 0.43 M☉ |
| Radius | 0.42 R☉ |
| Luminosity | 0.015[3] L☉ |
| Temperature | 3,100 K |
| Rotational velocity (v sin i) | 140 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Variability
editThe eclipsing binary nature of QS Virginis was discovered in 1997 during the Edinburgh-Cape Blue Object Survey for blue stellar objects in the southern hemisphere.[5]
Possible third body
editIn 2009 the discovery of an extrasolar planet in orbit around the binary star was announced, detected by variations in the timings of the eclipses of the two stars.[6] The planet was announced to have a minimum mass 6.4 times the mass of Jupiter, in an elliptical orbit 4.2 Astronomical Units away from binary.
Subsequent observations revealed that the timings were not following the pattern predicted by the planetary model. While the observed variations in eclipse times may be caused by a third body, the best fit model orbit is for an object with minimum mass 0.05 solar masses (about 50 times the mass of Jupiter) in a highly eccentric 14-year orbit.[7]
See also
editReferences
edit- ^ a b c d e f g O'Donoghue; Koen, C.; Kilkenny, D.; Stobie, R. S.; et al. (2003). "The DA+dMe eclipsing binary EC13471-1258: its cup runneth over ... just". Monthly Notices of the Royal Astronomical Society. 345 (2): 506–528. arXiv:astro-ph/0307144. Bibcode:2003MNRAS.345..506O. doi:10.1046/j.1365-8711.2003.06973.x. S2CID 17408072.
- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Calculated from the effective temperature and radius
- ^ "QS Vir". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-11-16.
- ^ Kilkenny, D.; et al. (1997). "The Edinburgh-Cape Blue Object Survey - II. Zone 1 - the North Galactic CAP". Monthly Notices of the Royal Astronomical Society. 287 (4): 867–893. Bibcode:1997MNRAS.287..867K. doi:10.1093/mnras/287.4.867.
- ^ Qian, S.-B.; Liao, W.-P.; Zhu, L.-Y.; Dai, Z.-B.; et al. (2009). "A giant planet in orbit around a magnetic-braking hibernating cataclysmic variable". Monthly Notices of the Royal Astronomical Society. 401 (1): L34–L38. Bibcode:2010MNRAS.401L..34Q. doi:10.1111/j.1745-3933.2009.00780.x.
- ^ Parsons, S. G.; Marsh, T. R.; Copperwheat, C. M.; Dhillon, V. S.; et al. (2010). "Orbital Period Variations in Eclipsing Post Common Envelope Binaries". Monthly Notices of the Royal Astronomical Society. 407 (4): 2362–2382. arXiv:1005.3958. Bibcode:2010MNRAS.407.2362P. doi:10.1111/j.1365-2966.2010.17063.x. S2CID 96441672.