A Chandra Observation of the Massive Star-Forming
... XLFs constructed from hard band luminosities and total luminosities the ACIS-I FOV compared to those (449) detected in X-ray (uncorrected for absorption) compared with Orion XLF from COUP Three color composite MSX image of NGC 6357. Central cavity and bright nebulosities are clearly seen. ...
... XLFs constructed from hard band luminosities and total luminosities the ACIS-I FOV compared to those (449) detected in X-ray (uncorrected for absorption) compared with Orion XLF from COUP Three color composite MSX image of NGC 6357. Central cavity and bright nebulosities are clearly seen. ...
64 Exercise Solutions_e
... Options A and C are incorrect. Since the stars have the same luminosity, Q must be farther away so that it looks fainter. By , the intensity is inversely proportional to the distance squared. Therefore, Q’s distance should be 5 times that of P such that its brightness is 1/52 = 1/25 that of P. ...
... Options A and C are incorrect. Since the stars have the same luminosity, Q must be farther away so that it looks fainter. By , the intensity is inversely proportional to the distance squared. Therefore, Q’s distance should be 5 times that of P such that its brightness is 1/52 = 1/25 that of P. ...
Likely formation of general relativistic radiation pressure supported
... upper limits were the full story, we would not have had stars of masses as large as ∼ 100M⊙ . Further, there are interstellar gas clouds of mass probably as large as ∼ 106 M⊙ . The reason behind the existence of non-singular cosmic objects with such higher masses is that they are not supported by co ...
... upper limits were the full story, we would not have had stars of masses as large as ∼ 100M⊙ . Further, there are interstellar gas clouds of mass probably as large as ∼ 106 M⊙ . The reason behind the existence of non-singular cosmic objects with such higher masses is that they are not supported by co ...
Document
... young close-by BHs can be estimated basing on data on massive runaway stars For two cases we obtained relatively small error boxes For HD 64760 and for λ Cep we obtained very large error boxes (40-50o) Several EGRET sources inside ...
... young close-by BHs can be estimated basing on data on massive runaway stars For two cases we obtained relatively small error boxes For HD 64760 and for λ Cep we obtained very large error boxes (40-50o) Several EGRET sources inside ...
Homework # 1
... Go to website for Black Body Radiation. This will start up a little program that shows the energy output of solid objects (black bodies) at various temperatures. The sliding scale at the bottom changes the temperature of the black body and the resulting energy output for a range of wavelengths is sh ...
... Go to website for Black Body Radiation. This will start up a little program that shows the energy output of solid objects (black bodies) at various temperatures. The sliding scale at the bottom changes the temperature of the black body and the resulting energy output for a range of wavelengths is sh ...
ph600-12 - University of Kent
... We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We us ...
... We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We us ...
Supernova Stalking - Susanna Kumlien Reportage
... in a new way. All researchers who want to study a star’s death face the challenge of supernova explosions being uncommon. We must therefore observe many galaxies. The unique feature of our project is that we scan the same part of the sky more often. In this way, we find supernovae shortly after they ...
... in a new way. All researchers who want to study a star’s death face the challenge of supernova explosions being uncommon. We must therefore observe many galaxies. The unique feature of our project is that we scan the same part of the sky more often. In this way, we find supernovae shortly after they ...
Krupp (1999) broadly defines the interdisciplinary field
... locations of cupule rims and shadows. The resulting diagram was compared to a computer simulation of the night sky as seen from the latitude of Rapa Nui (Lane, 1996). ...
... locations of cupule rims and shadows. The resulting diagram was compared to a computer simulation of the night sky as seen from the latitude of Rapa Nui (Lane, 1996). ...
Variable Stars – II. Pulsating stars
... In this case the star is unstable to pulsation and any small variation, will be reinforced – the pulsation will grow until the energy input by the κ-mechanism reaches a limit. The star will then be pulsating with a stable period and amplitude. Note that the partial ionization zones can be near the s ...
... In this case the star is unstable to pulsation and any small variation, will be reinforced – the pulsation will grow until the energy input by the κ-mechanism reaches a limit. The star will then be pulsating with a stable period and amplitude. Note that the partial ionization zones can be near the s ...
Planet-like Companion to a Brown Dwarf
... orbiting the star slowly clumps to form a rocky planet ten times larger than Earth, which then collects a large gaseous envelope. In the second—the disk instability model—a lump of gas in the disk quickly collapses to form an object the size of a giant gas planet. In the third and distinctly differe ...
... orbiting the star slowly clumps to form a rocky planet ten times larger than Earth, which then collects a large gaseous envelope. In the second—the disk instability model—a lump of gas in the disk quickly collapses to form an object the size of a giant gas planet. In the third and distinctly differe ...
Synthetic Stellar Populations Encyclopedia of Astronomy & Astrophysics eaa.iop.org Guy Worthey
... comes from stars near the main sequence turnoff or from post-main-sequence stars. All of these stars have nearly the same mass (because post-main-sequence lifetimes are relatively short) so there is little mass differential for the IMF to work on. Since we do not know how much the IMF varies from en ...
... comes from stars near the main sequence turnoff or from post-main-sequence stars. All of these stars have nearly the same mass (because post-main-sequence lifetimes are relatively short) so there is little mass differential for the IMF to work on. Since we do not know how much the IMF varies from en ...
Document
... The bigger the Star the smaller its lifespan • The most massive stars have the shortest lives. • Stars that are 25 to 50 times that of the Sun live for only a few million years. • Stars like our Sun live for about 10 billion years (our Sun is about half way through its life cycle!) • Stars less mas ...
... The bigger the Star the smaller its lifespan • The most massive stars have the shortest lives. • Stars that are 25 to 50 times that of the Sun live for only a few million years. • Stars like our Sun live for about 10 billion years (our Sun is about half way through its life cycle!) • Stars less mas ...
Is the central binary system of the planetary nebula Henize 2
... interestingly, in the study by Weidmann and Gamen (2011) there are several PNe that show a wide He II 5412 Å absorption line with a weak emission feature in the center of the wide absorption line. This forms a spectral structure similar to that of Henize 2–428. The most noticeable examples of this ...
... interestingly, in the study by Weidmann and Gamen (2011) there are several PNe that show a wide He II 5412 Å absorption line with a weak emission feature in the center of the wide absorption line. This forms a spectral structure similar to that of Henize 2–428. The most noticeable examples of this ...
A massive hypergiant star as the progenitor of the supernova SN
... shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with genuine supernova explosions. b, Collisions between a faster massive ejec ...
... shells4,28, along with very luminous optical displays, during which the luminosity of the star may increase by an order of magnitude or more. These events (sometimes called supernova impostors26) can therefore be confused with genuine supernova explosions. b, Collisions between a faster massive ejec ...
Document
... Bellatrix: "Gamma Orionis“ is the twenty-second brightest star in the night sky. Bellatrix is considered a blue giant, though it is too small to explode in a supernova. Its luminosity is derived from its high temperature rather than its radius. Bellatrix serves as Orion's "left shoulder. ...
... Bellatrix: "Gamma Orionis“ is the twenty-second brightest star in the night sky. Bellatrix is considered a blue giant, though it is too small to explode in a supernova. Its luminosity is derived from its high temperature rather than its radius. Bellatrix serves as Orion's "left shoulder. ...
Document
... Our Milky Way I. Select bright objects that you can see throughout the Milky Way and trace their directions and distances II. Observe objects at wavelengths other than visible (to eliminate problems caused by dust, gas, other galactic bodies, etc), and catalogue their directions and distances ...
... Our Milky Way I. Select bright objects that you can see throughout the Milky Way and trace their directions and distances II. Observe objects at wavelengths other than visible (to eliminate problems caused by dust, gas, other galactic bodies, etc), and catalogue their directions and distances ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges 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 born 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 life. 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 through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.