GS 2000+25 is an X-ray binary system in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Vulpecula Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the Summer Triangle (an ...

, consisting of a late K-type star and a

black hole A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...

. It is also an X-ray nova.

Properties

Because the black hole is more massive than the companion star, it is the primary of the system. The black hole has a mass of about 5

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 while the companion has a mass of about 0.5 solar masses. Because the companion star has a low mass, the system is a low-mass X-ray binary.

References

Vulpecula Vulpeculae, QZ Stellar black holes K-type main-sequence stars Novae X-ray binaries {{multi-star-stub

Properties

See also

References