|
Sw J1745-26
Swift J1745-26 is a stellar-mass black hole located a few degrees from the center of the Milky Way galaxy toward the constellation Sagittarius. It was discovered by NASA's Swift satellite on September 16, 2012 due to the detection of an X-ray nova. The pattern of X-rays from the nova indicated that the central object was a black hole. Its name arises from the coordinates of its sky position. While astronomers do not know its precise distance, they think the object resides about 20,000 to 30,000 light-years away in the galaxy's inner region. Ground-based observatories have detected infrared and radio emissions from Swift J1745-26, but thick clouds of obscuring dust have prevented astronomers from catching Swift J1745-26 in visible light. Swift J1745-26 must be a member of a low-mass 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 no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-Ray Nova Reveals A New Black Hole In Our Galaxy
X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Röntgen, Wilhelm Conrad Röntgen, who discovered it in 1895 in science, 1895 and named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . X-ray wavelengths are shorter than those of ultraviolet rays and longer than those of gamma rays. There is no universally accepted, strict definition of the bounds of the X-ray band. Roughly, X-rays have a wavelength ranging from 10 Nanometre, nanometers to 10 Picometre, picometers, corresponding to frequency, frequencies in the range of 30 Hertz, petahertz to 30 Hertz, exahertz ( to ) and photon energies in the range of 100 electronvolt, eV to 100 keV, respectively. X-rays can penetrate many solid substances such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittarius (constellation)
Sagittarius is one of the constellations of the zodiac and is located in the Southern celestial hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations. Its old astronomical symbol is (♐︎). Its name is Latin for "archer". Sagittarius is commonly represented as a centaur pulling back a bow. It lies between Scorpius and Ophiuchus to the west and Capricornus and Microscopium to the east. The center of the Milky Way lies in the westernmost part of Sagittarius (see Sagittarius A). Visualizations As seen from the northern hemisphere, the constellation's brighter stars form an easily recognizable asterism known as "the Teapot". The stars δ Sgr (Kaus Media), ε Sgr (Kaus Australis), ζ Sgr (Ascella), and φ Sgr form the body of the pot; λ Sgr (Kaus Borealis) is the point of the lid; γ2 Sgr (Alnasl) is the tip of the spout; and σ Sgr (Nunki) and τ Sgr the handle. These same sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way Galaxy
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulge) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swift Satellite
Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/Visible light at the location of a burst. It was launched on 20 November 2004, aboard a Delta II launch vehicle. Headed by principal investigator Neil Gehrels until his death in February 2017, the mission was developed in a joint partnership between Goddard Space Flight Center (GSFC) and an international consortium from the United States, United Kingdom, and Italy. The mission is operated by Pennsylvania State University as part of NASA's Medium Explorer program (MIDEX). The burst detection rate is 100 per year, with a sensitivity ~3 times fainter than the BATSE detector aboard the Compton Gamma Ray Observatory. The Swift mission was launched with a nominal on-orbit lifetime of two years. Swift is a NASA MIDEX (medium-class Explorer) mission. It was the third to be lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft X-ray Transient
Soft X-ray transients (SXTs), also known as X-ray novae and black hole X-ray transients, are composed of a compact object (most commonly a black hole but sometimes a neutron star) and some type of "normal", low-mass star (i.e. a star with a mass of some fraction of the Sun's mass). These objects show dramatic changes in their X-ray emission, probably produced by variable transfer of mass from the normal star to the compact object, a process called accretion. In effect the compact object "gobbles up" the normal star, and the X-ray emission can provide the best view of how this process occurs. The "soft" name arises because in many cases there is strong soft (i.e. low-energy) X-ray emission from an accretion disk close to the compact object, although there are exceptions which are quite hard. Soft X-ray transients Cen X-4 and Aql X-1 were discovered by Hakucho, Japan's first X-ray astronomy satellite to be X-ray bursters. During active accretion episodes, called "outbursts", S ... [...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] |
Stellar Black Holes
Stellar means anything related to one or more stars (''stella''). The term may also refer to: Arts, entertainment, and media * ''Stellar'' (magazine), an Irish lifestyle and fashion magazine * Stellar Loussier, a character from ''Mobile Suit Gundam SEED Destiny'' * Dr. Stellar, a Big Bang Comics superhero * '' Stellar 7'', a game for the Apple II computer system * ''Stellar'' (film), a Canadian film Music * Stellar (group), a South Korean girl group * Stellar (New Zealand band), a New Zealand-based rock band * "Stellar" (song), a 2000 song by Incubus * Stellar Awards, awards for the gospel music industry Brands and enterprises * Stellar (payment network), a system for sending money through the internet * Stellar Group (construction company), a construction company in Florida, United States * Hasselblad Stellar, a compact digital camera * Hyundai Stellar, an automobile model * O2 XDA Stellar, an HTC mobile phone Other uses * Stellar Airpark, an airport near Chandler, Arizo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
