W Ursae MajorisW Ursae Majoris (W UMa) is the variable star designation for a binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of about 8, which is too faint to be seen with the naked eye. However, it can be viewed with a small telescope. Parallax measurements place it at a distance of roughly 169 light years (52 parsecs) from Earth.
Common envelopeIn astronomy, a common envelope (CE) is gas that contains a binary-star system. The gas does not rotate at the same rate as the embedded binary system. A system with such a configuration is said to be in a common-envelope phase or undergoing common-envelope evolution. During a common-envelope phase, the embedded binary system is subject to drag forces from the envelope, which cause the separation of the two stars to decrease.
Binary systemA binary system is a system of two astronomical bodies of the same kind that are comparable in size. Definitions vary, but typically require the center of mass to be located outside of either object. (See animated examples.) The most common kinds of binary system are binary stars and binary asteroids, but brown dwarfs, planets, neutron stars, black holes and galaxies can also form binaries.
Binary starA binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars are among the most important objects in astrophysics because they allow direct measurement of stellar masses and test theories of stellar evolution. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars using a telescope, in which case they are called visual binaries.
W Ursae Majoris variableA W Ursae Majoris variable, also known as a low mass contact binary, is a type of eclipsing binary variable star. These stars are close binaries of spectral types F, G, or K that share a common envelope of material and are thus in contact with one another. They are termed contact binaries because the two stars touch and transfer mass and energy through the connecting neck, although astronomer Robert E. Wilson argues that the term "overcontact" is more appropriate.
AW Ursae MajorisAW Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated AW UMa. It is an A-type W Ursae Majoris variable (W UMa) with an apparent visual magnitude of 6.83, which is near the lower limit of visibility to the naked eye. This is an eclipsing binary with the brightness dropping to magnitude 7.13 during the primary eclipse and to 7.08 with the secondary eclipse.
Effective temperatureThe effective temperature (akaET) of a body such as a star or planet is the temperature of a black body that would emit the same total energy as electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known.
Roche lobeIn astronomy, the Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star. It is an approximately teardrop-shaped region bounded by a critical gravitational equipotential, with the apex of the teardrop pointing towards the other star (the apex is at the L1 Lagrangian point of the system).
AstronomyAstronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation.
Gerard KuiperGerard Peter Kuiper ( ; born Gerrit Pieter Kuiper, Dutch:; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. The Kuiper belt is named after him. Kuiper is considered by many to be the father of modern planetary science. Early life and educationKuiper, the son of a tailor in the village of Tuitjenhorn in North Holland, had an early interest in astronomy.
44 Boötis44 Boötis, also known as i Boötis, is a triple star system in the constellationBoötes. It is approximately 41.6 light years from Earth. Its three components are designated 44 Boötis A (with the proper name Quadrans), 44 Boötis Ba, and 44 Boötis Bb. 44 Boötis B is a contact binary of the W Ursae Majoris type. It is the nearest contact binary star. Nomenclature44 Boötis is the star's Flamsteed designation; it also has the Bayer designationi Boötis.*As an Amazon Associate I earn from qualifying purchases.