Diapositiva 1
... Rotation on MS M > 1.6M or B-V < 0.25-0.3: Little or no stellar activity No evidence of significant angular momentum loss There is no trend on rotation with age (vsin i ~ cte) M < 1.6M or B-V > 0.25-0.3: Stellar activity does not depend on age or rotation Very slow angular momentum ...
... Rotation on MS M > 1.6M or B-V < 0.25-0.3: Little or no stellar activity No evidence of significant angular momentum loss There is no trend on rotation with age (vsin i ~ cte) M < 1.6M or B-V > 0.25-0.3: Stellar activity does not depend on age or rotation Very slow angular momentum ...
The Application of Forbidden Line X-Ray Diagnostics to the Hot Star
... The processes by which hot stars emit X-rays are not yet fully understood. While dimmer stars like the Sun generate Xrays through magnetic confinement of the corona, it is generally thought that the X-rays from hot stars are created in radiatively driven stellar wind shocks. ...
... The processes by which hot stars emit X-rays are not yet fully understood. While dimmer stars like the Sun generate Xrays through magnetic confinement of the corona, it is generally thought that the X-rays from hot stars are created in radiatively driven stellar wind shocks. ...
Stars
... Suppose the radius of the Sun increased by a factor of 4 but the rate of power generated by fusion remained the same, how would the surface temperature of the Sun change? ...
... Suppose the radius of the Sun increased by a factor of 4 but the rate of power generated by fusion remained the same, how would the surface temperature of the Sun change? ...
The Origin of Light
... the whole of space. Cosmic events, perhaps pressure waves from explosions, trigger the coming together of bunches of hydrogen atoms that then, through gravity, attract other atoms. Increasing amounts of matter, and therefore increased gravity, lead to a rise in pressure at the center. High pressures ...
... the whole of space. Cosmic events, perhaps pressure waves from explosions, trigger the coming together of bunches of hydrogen atoms that then, through gravity, attract other atoms. Increasing amounts of matter, and therefore increased gravity, lead to a rise in pressure at the center. High pressures ...
COMPONENTS OF THE UNIVERSE
... it is. As stars age, they fall outside the main sequence and become giants or supergiants, depending on their mass. As less-massive stars die, they become relatively tiny white dwarfs. More massive stars die by exploding into a powerful supernova. (Even smaller stars live for billions of years. The ...
... it is. As stars age, they fall outside the main sequence and become giants or supergiants, depending on their mass. As less-massive stars die, they become relatively tiny white dwarfs. More massive stars die by exploding into a powerful supernova. (Even smaller stars live for billions of years. The ...
smallest exoplanet - Forsyth Astronomical Society
... Astronomers plan to observe a rare cosmic cradle for the universe's largest stars, - baby bruisers that grow up to have 50 times the Sun's mass. The Carina cloud is also unusual in its rapid pace of collapse and the amount of dust and gas, an amount so large it eclipsed the large stars that had alre ...
... Astronomers plan to observe a rare cosmic cradle for the universe's largest stars, - baby bruisers that grow up to have 50 times the Sun's mass. The Carina cloud is also unusual in its rapid pace of collapse and the amount of dust and gas, an amount so large it eclipsed the large stars that had alre ...
Cooling of Compact Stars
... The Astrophysical Journal V 749 N1 Chris L. Fryer et al. 2012 ApJ 749 91 ...
... The Astrophysical Journal V 749 N1 Chris L. Fryer et al. 2012 ApJ 749 91 ...
How to Detect Black Holes
... stated that a cluster of neutron stars would have similar effects on their neighbors (the accretion disk and resulting X-ray emission, for example). Another said that it was a cluster of smaller black holes as opposed to one large one. And a third stated that SgrA* is a large mass of heavy neutrinos ...
... stated that a cluster of neutron stars would have similar effects on their neighbors (the accretion disk and resulting X-ray emission, for example). Another said that it was a cluster of smaller black holes as opposed to one large one. And a third stated that SgrA* is a large mass of heavy neutrinos ...
Mass Segregation in Globular Clusters
... A second, related prediction is that more-massive stars should sink toward the center of a cluster because of their lower speeds. This mass segregation should occur because the maximum radius to which a star can “climb” against the force of gravity pulling it toward the middle is only dependent upo ...
... A second, related prediction is that more-massive stars should sink toward the center of a cluster because of their lower speeds. This mass segregation should occur because the maximum radius to which a star can “climb” against the force of gravity pulling it toward the middle is only dependent upo ...
Project 4: The HR diagram. Open clusters
... When luminosity is plotted as a function of the temperature for a large number of stars, stars do not fall randomly on the graph; rather they are confined to specific regions. This tells you that there is some physical relationship between the luminosity and temperature of a star. From the figure ...
... When luminosity is plotted as a function of the temperature for a large number of stars, stars do not fall randomly on the graph; rather they are confined to specific regions. This tells you that there is some physical relationship between the luminosity and temperature of a star. From the figure ...
Dr. Amanda Karakas and Prof. John Lattanzio
... Asymptotic Giant Branch stars • The asymptotic giant branch is the last nuclear burning phase for stars with mass < 8Msun • AGB stars are cool (~3000 K) evolved giants, spectral types M, S, C ...
... Asymptotic Giant Branch stars • The asymptotic giant branch is the last nuclear burning phase for stars with mass < 8Msun • AGB stars are cool (~3000 K) evolved giants, spectral types M, S, C ...
Stellar populations and dynamics in the Milky Way galaxy
... there need be no correlation between the time of a star’s formation – which they infer from a star’s metallicity – and its present orbital properties. In a non-rotating pressuresupported system, all stars formed would be on highly radial orbits, as a star has too small a surface area to be pressure ...
... there need be no correlation between the time of a star’s formation – which they infer from a star’s metallicity – and its present orbital properties. In a non-rotating pressuresupported system, all stars formed would be on highly radial orbits, as a star has too small a surface area to be pressure ...
Lecture 7 February 9
... x-ray photon at 100A than the infrared light photons emitted by every living human? (Assuming 10,000nm wavelength of infrared light). • A. Ten times as powerful. • B. A hundred times more powerful. • C. A thousand times more powerful. • D. 1x1012 (a trillion) times more powerful. • E. 1x1015 (a quad ...
... x-ray photon at 100A than the infrared light photons emitted by every living human? (Assuming 10,000nm wavelength of infrared light). • A. Ten times as powerful. • B. A hundred times more powerful. • C. A thousand times more powerful. • D. 1x1012 (a trillion) times more powerful. • E. 1x1015 (a quad ...
2.1 Introduction
... associated with the Carina nebula at a distance of 3.2 kpc. It is immediately obvious from these images that: (a) stars have a range of colours, and (b) some stars are intrinsically brighter than others. More generally, we can make a list of what we may consider to be the most important physical pro ...
... associated with the Carina nebula at a distance of 3.2 kpc. It is immediately obvious from these images that: (a) stars have a range of colours, and (b) some stars are intrinsically brighter than others. More generally, we can make a list of what we may consider to be the most important physical pro ...
Ch 28 Class Notes
... A small star grouping, or sub-grouping of a constellation is called an _____________________. We are familiar with the constellation known as Ursa Major (the Great Bear). Within _____________________________ is the Big Dipper. The Big Dipper is an asterism in the shape of a dipper and handle. The tw ...
... A small star grouping, or sub-grouping of a constellation is called an _____________________. We are familiar with the constellation known as Ursa Major (the Great Bear). Within _____________________________ is the Big Dipper. The Big Dipper is an asterism in the shape of a dipper and handle. The tw ...
ASTRONOMY 301 EXAMPLES OF TEST
... radio waves, infrared and blue light, ultraviolet radiation, and X-rays. all of the above. ...
... radio waves, infrared and blue light, ultraviolet radiation, and X-rays. all of the above. ...
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.