QS Virginis (abbreviated QS Vir) is an

eclipsing binary A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

system approximately 163

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s away from the Sun, forming a

cataclysmic variable In astronomy, cataclysmic variable stars (CVs) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state. They were initially called novae (), since ones with an outburst brightness visible to ...

. The system comprises an eclipsing

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...

and

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

that orbit each other every 3.37

hour An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as of a day and scientifically reckoned between 3,599 and 3,601 seconds, depending on the speed of Earth's rotation. There are 60 minutes in an hour, and 24 ho ...

Variability

The eclipsing binary nature of QS Virginis was discovered in 1997 during the

Edinburgh-Cape Blue Object Survey The Edinburgh-Cape Blue Object Survey (or EC in astronomical notation)C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, ''Asteroseismology'' (2010), p. 105. is a major astronomical survey to discover blue stellar objects brighter than B~18 in the so ...

for blue stellar objects in the southern hemisphere.

Possible third body

In 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. The planet was announced to have a minimum mass 6.4 times the mass of

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

, in an elliptical orbit 4.2

Astronomical Unit The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...

s 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 mass The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

es (about 50 times the mass of Jupiter) in a highly eccentric 14-year orbit.

References

{{Stars of Virgo Virgo (constellation) Eclipsing binaries Virginis, QS White dwarfs M-type main-sequence stars Hypothetical planetary systems

Variability

Possible third body

See also

References