Supermassive black holes accreting stars through tidal disruption in
... • In axisymmetric case, Jz≤Jlc. Because J is not conserved, boundary in J dimension can be a few times larger than Jlc. (Magorrian & Tremaine, 1999) • Measured in (E,J,Jz) phase space by performing scattering experiment. ...
... • In axisymmetric case, Jz≤Jlc. Because J is not conserved, boundary in J dimension can be a few times larger than Jlc. (Magorrian & Tremaine, 1999) • Measured in (E,J,Jz) phase space by performing scattering experiment. ...
Student Exploration Sheet: Growing Plants
... A star orbited by a large planet will move in a small circle. This will cause its spectrum to be slightly redshifted part of the time and blueshifted at other times. ...
... A star orbited by a large planet will move in a small circle. This will cause its spectrum to be slightly redshifted part of the time and blueshifted at other times. ...
RR animation
... with a mass of around half the Sun's. They are thought to have previously shed mass and consequently, they were once stars with similar or slightly less mass than the Sun, around 0.8 solar masses. RR Lyrae stars pulse in a manner similar to Cepheid variables, so the mechanism for the pulsation is th ...
... with a mass of around half the Sun's. They are thought to have previously shed mass and consequently, they were once stars with similar or slightly less mass than the Sun, around 0.8 solar masses. RR Lyrae stars pulse in a manner similar to Cepheid variables, so the mechanism for the pulsation is th ...
Astronomy (stars, galaxies and the Universe)
... Groups of stars that form a pattern The revolution of the Earth around the Sun cause different constellations to be seen at different times of the year Stars located above the north and south poles, called circumpolar stars, appear to move in circles above the horizon each night Astronomers use cons ...
... Groups of stars that form a pattern The revolution of the Earth around the Sun cause different constellations to be seen at different times of the year Stars located above the north and south poles, called circumpolar stars, appear to move in circles above the horizon each night Astronomers use cons ...
Exploring The Universe
... strong radio signal. This object was called a quasar. • quasar quasi-stellar radio sources; very luminous objects that produce energy at a high rate and that are thought to be the most distant objects in the universe • Each quasar has a huge central black hole and a large disk of gas and dust around ...
... strong radio signal. This object was called a quasar. • quasar quasi-stellar radio sources; very luminous objects that produce energy at a high rate and that are thought to be the most distant objects in the universe • Each quasar has a huge central black hole and a large disk of gas and dust around ...
Stellar Physics 1
... Stellar Physics 1 14. Which of the following statements is true about eclipsing binary systems? A. A secondary maximum occurs when a smaller star eclipses a larger star. B. A primary minimum occurs when a smaller star eclipses a larger one. C. A secondary minimum occurs when a smaller star eclipses ...
... Stellar Physics 1 14. Which of the following statements is true about eclipsing binary systems? A. A secondary maximum occurs when a smaller star eclipses a larger star. B. A primary minimum occurs when a smaller star eclipses a larger one. C. A secondary minimum occurs when a smaller star eclipses ...
TAP 702- 6: Binary stars - Teaching Advanced Physics
... In many binary stars, the two stars are not perfectly lined up when seen from Earth. This means that there will not be any dimming or brightening of the light, because the dimmer star will not block out the light from the brighter one. How might an astronomer tell, from the spectrum, that there are ...
... In many binary stars, the two stars are not perfectly lined up when seen from Earth. This means that there will not be any dimming or brightening of the light, because the dimmer star will not block out the light from the brighter one. How might an astronomer tell, from the spectrum, that there are ...
Stellar Winds and Mass Loss
... These can explain hot bubble around hot stars, ring nebulae around WR stars, and ultra compact HII regions, as well as PNe ...
... These can explain hot bubble around hot stars, ring nebulae around WR stars, and ultra compact HII regions, as well as PNe ...
From Rubber Bands to Big Bangs The Universe has been
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
Stellar Evolution
... • all the stars formed at about the same time Determining the distance and age to a globular cluster is much easier than trying to find the distances and ages of a million random stars! Laboratories for understanding how stars of different masses evolve ASTR 1120: Spring 2005 ...
... • all the stars formed at about the same time Determining the distance and age to a globular cluster is much easier than trying to find the distances and ages of a million random stars! Laboratories for understanding how stars of different masses evolve ASTR 1120: Spring 2005 ...
AST1001.ch13
... What happens to a white dwarf when it accretes enough matter to reach the 1.4 MSun limit? A. It explodes. B. It collapses into a neutron star. C. It gradually begins fusing carbon in its core. ...
... What happens to a white dwarf when it accretes enough matter to reach the 1.4 MSun limit? A. It explodes. B. It collapses into a neutron star. C. It gradually begins fusing carbon in its core. ...
transparencies
... one site into the star propagates with a finite velocity inside the star and a sudden modification of the radius occurs. Non radial modes develops and GW bursts can be emitted before a new equilibrium configuration is reached ...
... one site into the star propagates with a finite velocity inside the star and a sudden modification of the radius occurs. Non radial modes develops and GW bursts can be emitted before a new equilibrium configuration is reached ...
document
... Planetary nebula, NGC 2392 (The Eskimo Nebula) The word “nebula” refers to any cloud of interstellar gas and dust. Through small telescopes, these objects looked like the planets Uranus and Neptune, and so early astronomers called them “planetary” nebulae. Astronomers now know that they have nothin ...
... Planetary nebula, NGC 2392 (The Eskimo Nebula) The word “nebula” refers to any cloud of interstellar gas and dust. Through small telescopes, these objects looked like the planets Uranus and Neptune, and so early astronomers called them “planetary” nebulae. Astronomers now know that they have nothin ...
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.