|
QX Normae
QX Normae is an active low mass X ray binary in the constellation Norma Norma may refer to: * Norma (given name), a given name (including a list of people with the name) Astronomy * Norma (constellation) *555 Norma, a minor asteroid * Cygnus Arm or Norma Arm, a spiral arm in the Milky Way galaxy Geography *Norma, Laz .... It is composed of a neutron star and a star smaller and cooler than the Sun. The X-ray component, known as 4U 1608–52, was discovered in the early 1970s, while the visual component, QX Normae, was discovered in 1977. By analysing the interstellar extinction between Earth and the system, Güver and colleagues calculated the most likely distance to be 5.8 kpc (19,000 light-years), and the neutron star's mass to be 1.74 ± 0.14 times that of the Sun and radius to be a mere 9.3 ± 1.0 km. References {{DEFAULTSORT:QX Normae Norma (constellation) Normae, QX ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norma (constellation)
Norma is a small constellation in the Southern Celestial Hemisphere between Ara and Lupus, one of twelve drawn up in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. Its name is Latin for normal, referring to a right angle, and is variously considered to represent a rule, a carpenter's square, a set square or a level. It remains one of the 88 modern constellations. Four of Norma's brighter stars—Gamma, Delta, Epsilon and Eta—make up a square in the field of faint stars. Gamma2 Normae is the brightest star with an apparent magnitude of 4.0. Mu Normae is one of the most luminous stars known, with a luminosity between a quarter million and one million times that of the Sun. Four star systems are known to harbour planets. The Milky Way passes through Norma, and the constellation contains eight open clusters visible to observers with binoculars. The constellation also hosts Abell 3627, also called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Binary
X-ray binaries are a class of binary stars that are luminous in X-rays. The X-rays are produced by matter falling from one component, called the ''donor'' (usually a relatively normal star), to the other component, called the ''accretor'', which is very compact: a neutron star or black hole. The infalling matter releases gravitational potential energy, up to several tenths of its rest mass, as X-rays. (Hydrogen fusion releases only about 0.7 percent of rest mass.) The lifetime and the mass-transfer rate in an X-ray binary depends on the evolutionary status of the donor star, the mass ratio between the stellar components, and their orbital separation. An estimated 1041 positrons escape per second from a typical low-mass X-ray binary. Classification X-ray binaries are further subdivided into several (sometimes overlapping) subclasses, that perhaps reflect the underlying physics better. Note that the classification by mass (high, intermediate, low) refers to the optically vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
