40 Eridani is a triple star system in the constellation of Eridanus, abbreviated 40 Eri. It has the Bayer designation Omicron2 Eridani, which is Latinized from ο2 Eridani and abbreviated Omicron2 Eri or ο2 Eri. Based on parallax measurements taken by the Gaia mission, it is about 16.3 light-years from the Sun.
PSR B1620−26 is a binary star system located at a distance of 3,800 parsecs in the globular cluster of Messier 4 in the constellation of Scorpius. The system is composed of a pulsar and a white dwarf star. As of 2000, the system is also confirmed to have an exoplanet orbiting the two stars.
Luyten 726-8, also known as Gliese 65, is a binary star system that is one of Earth's nearest neighbors, at about 8.7 light years from Earth in the constellation Cetus. The two component stars are both flare stars with the variable star designations BL Ceti and UV Ceti.
DQ Herculis, or Nova Herculis 1934, was a slow, bright nova occurring in the northern constellation of Hercules in December 1934. This cataclysmic variable star was discovered on 13 December 1934 by J. P. M. Prentice from Stowmarket, Suffolk. It reached peak brightness on 22 December 1934 with an apparent magnitude of 1.5. The nova remained visible to the naked eye for several months.
AB Doradus is a pre-main-sequence quadruple star system in the constellation Dorado. The primary is a flare star that shows periodic increases in activity.
AM Herculis is a binary variable star located in the constellation Hercules. This star, along with the star AN Ursae Majoris, is the prototype for a category of cataclysmic variable stars called polars, or AM Her type stars.
Gliese 86 is a K-type main-sequence star approximately 35 light-years away in the constellation of Eridanus. It has been confirmed that a white dwarf orbits the primary star. In 1998 the European Southern Observatory announced that an extrasolar planet was orbiting the star.
EX Hydrae is a variable star classified as an eclipsing intermediate polar-type cataclysmic variable, specifically of the DQ Herculis type. The system varies in apparent magnitude from 9.6 to 14. The system consists of a white dwarf primary and an M-type secondary, of masses of 0.4–0.7 M☉ and 0.07–0.10 M☉ respectively. The orbital period is 98.25696 minutes (0.068233846 days). The system is 65±11 parsecs distant, making EX Hya one of the closest cataclysmic variable stars. The cataclysmic outbursts appear to be caused by accretion of material from the M-star to the white dwarf.
QS Virginis is an eclipsing binary system approximately 163 light-years away from the Sun, forming a cataclysmic variable. The system comprises an eclipsing white dwarf and red dwarf that orbit each other every 3.37 hours.
DP Leonis is a binary star system in the equatorial constellation of Leo. It is a variable star that ranges in apparent visual magnitude from 17.5 down to 19. The system is located at a distance of approximately 990 light-years from the Sun based on parallax. It is a cataclysmic variable star of the AM Herculis-type also known as polars. The system comprises an eclipsing white dwarf and red dwarf in tight orbit and an extrasolar planet. This eclipsing variable was discovered by P. Biermann and associates in 1982 as the optical counterpart to the EINSTEIN X-ray source E1114+182.
AN Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major. It is a variable star, with AN Ursae Majoris being the variable star designation, and ranges in brightness from 14.90 down to 20.2. Even at its peak brightness though, the system is much too faint to be visible to the naked eye. Based on parallax measurements, the system is located roughly 1,050 light years away from the Sun.
PSR J1719−1438 b is an extrasolar planet that was discovered on August 25, 2011, in orbit around PSR J1719−1438, a millisecond pulsar. The pulsar planet is most likely composed largely of crystalline carbon but with a density far greater than diamond. PSR J1719-1438 b orbits so closely to its host star that its orbit would fit inside the Sun. The existence of such carbon planets had been theoretically postulated.
Tau9 Eridani is a binary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.63. The distance to this system can be estimated using the parallax method, which yields a value of roughly 327 light years.
CE Gruis is a faint binary star system in the constellation Grus. It is a variable star, with a B-band brightness that ranges from a peak magnitude of 17.4 down to a minimum of 19.5 over a period of 108.6 minutes. The system is composed of a white dwarf and donor star, locked into a close, synchronous orbit. In such systems, known as polars, material from the donor star does not form an accretion disc around the white dwarf because of its intense magnetic field, but rather streams directly onto it along columns.
66 Eridani is a binary star in the constellation of Eridanus. The combined apparent magnitude of the system is 5.12 on average. Parallax measurements by Hipparcos put the system at some 309 light-years away.
QS Telescopii is a faint, well-studied binary star system in the southern constellation Telescopium. It is composed of a white dwarf and main sequence donor star, locked into a close, circular orbit facing one another. Known as polars, material from the donor star does not form an accretion disk around the white dwarf, but rather streams directly onto it. This is due to the presence of the white dwarf's strong magnetic field. The pair undergo frequent shifts between a high and low accretion states, and it shifts between single and double accretion poles. The main pole is partially self-eclipsing.
UZ Fornacis is a binary star in the constellation of Fornax. It appears exceedingly faint with a maximum apparent magnitude 17.0. Its distance, as measured by Gaia using the parallax method, is about 780 light-years.
BG Canis Minoris is a binary star system in the equatorial constellation of Canis Minor, abbreviated BG CMi. With an apparent visual magnitude that fluctuates around 14.5, it is much too faint to be visible to the naked eye. Parallax measurements provide a distance estimate of approximately 2,910 light years from the Sun.
QQ Vulpeculae is a cataclysmic variable binary star system in the northern constellation of Vulpecula, abbreviated QQ Vul. It has a brightness that fluctuates around an apparent visual magnitude of 14.7, which is too faint to be viewed with the naked eye. The distance to this system is approximately 981 light years based on parallax measurements.
YY Draconis and DO Draconis are separate identifiers for what is likely the same cataclysmic variable system in the northern constellation of Draco, abbreviated YY Dra and DO Dra, respectively. The DO Dra binary star system is classified as a U Geminorum variable that ranges in luminosity from an apparent visual magnitude of 10.0 down to 15.1. It is located at a distance of approximately 639 light years from the Sun.
