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Arcus (satellite)
Arcus is a proposed X-ray space observatory proposed to NASA's Explorer program, Medium Explorer (MIDEX) class. The Arcus mission would study galaxies and galaxy clusters using high-resolution X-ray spectroscopy to characterize the interactions between these objects and the diffuse hot gas that permeates them. The Principal investigator is Randall Smith at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts; the project has significant contributions from the Massachusetts Institute of Technology, cosine Measurement Systems (Warmond NL), Penn State, and the Max Planck Institute for Extraterrestrial Physics. Overview Arcus's spectrograph was originally intended to fly on the cancelled International X-ray Observatory (IXO). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supermassive Black Hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical objects that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, not even light. Observational evidence indicates that almost every large galaxy has a supermassive black hole at its Central massive object, center. For example, the Milky Way has a Galactic Center#Supermassive black hole, supermassive black hole in its Galactic Center, corresponding to the Astronomical radio source, radio source Sagittarius A*. Accretion (astrophysics), Accretion of Interstellar medium, interstellar gas onto supermassive black holes is the process responsible for powering Active galactic nucleus, active galactic nuclei (AGNs) and quasars. Two supermassive black holes have been directly imaged by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Evolution
Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are formed from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star. Nuclear fusion powers a star for most of its existence. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Dust Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are called meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (such as in the zodiacal cloud) and circumplanetary dust (such as in a planetary ring). There are several methods to obtain space dust measurement. In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach the Earth's surface every year, |
PennState
The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High School of Pennsylvania, Penn State became the state's only Land-grant university, land-grant university in 1863. Today, Penn State is a major research university which conducts teaching, research, and public service. Its instructional mission includes undergraduate, graduate, professional and continuing education offered through resident instruction and online delivery. The University Park campus has been labeled one of the "Public Ivy, Public Ivies", a publicly funded university considered as providing a quality of education comparable to those of the Ivy League. In addition to its land-grant designation, it also participates in the sea-grant, space-grant, and sun-grant research consortia; it is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEOStar
Star Bus is a satellite bus family of Orbital ATK. It was originally developed by Thomas van der Heyden, co-founder of CTAI, and later sold to and manufactured by Orbital Sciences Corporation. History The first satellite program based on the Star Bus platform, developed by Thomas van der Heyden for the Indonesian Direct Broadcast program IndoVision, was IndoStar-1 IndoStar-1, also known as Cakrawarta-1, was a communication satellite that was launched the evening of November 12, 1997 at 21:48 GMT aboard an Ariane 44L-3 rocket from Kourou, French Guiana. As the first direct broadcasting satellite (DBS) in ..., which was launched in November 1997. Variants See also * GEOStar-2 References Further reading * * Satellite buses Orbital Sciences Corporation {{US-spacecraft-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
