Massive star formation in 100000 years from turbulent and
... ∼ 8 M⊙ ) are fundamental to the evolution of galaxies, because they produce heavy elements, inject energy into the interstellar medium, and possibly regulate the star formation rate. The individual star formation time, t∗f , determines the accretion rate of the star; the value of the former quantity ...
... ∼ 8 M⊙ ) are fundamental to the evolution of galaxies, because they produce heavy elements, inject energy into the interstellar medium, and possibly regulate the star formation rate. The individual star formation time, t∗f , determines the accretion rate of the star; the value of the former quantity ...
Hungry Young Stars: A New Explanation for the FU Ori Outbursts
... • We provide an explanation for the origin of FU Ori bursts. • A young star devours embryos that form in the disk, resulting in colossal bursts of luminosity. This process repeats as long as nebular material rains onto the disk. • The new feature in our model is the self-consistent formation and evo ...
... • We provide an explanation for the origin of FU Ori bursts. • A young star devours embryos that form in the disk, resulting in colossal bursts of luminosity. This process repeats as long as nebular material rains onto the disk. • The new feature in our model is the self-consistent formation and evo ...
read in advance to speed your work
... stars in Orion (Table II). Plot the MV values (MV again is simply absolute magnitude, M, with the subscript indicating that the magnitude is measured in the visual part of the spectrum) against the spectral classification for the first 8 stars in Table II. Make carefully positioned round points just ...
... stars in Orion (Table II). Plot the MV values (MV again is simply absolute magnitude, M, with the subscript indicating that the magnitude is measured in the visual part of the spectrum) against the spectral classification for the first 8 stars in Table II. Make carefully positioned round points just ...
Review for Astronomy 3 Midterm #2
... Novae occur in systems consisting of a white dwarf with a main sequence/red giant companion. The white dwarf will sometimes “steal matter” from its companion, and eventually will have enough hydrogen on its surface for that hydrogen to begin to fuse to helium. It will do this very quickly and then ...
... Novae occur in systems consisting of a white dwarf with a main sequence/red giant companion. The white dwarf will sometimes “steal matter” from its companion, and eventually will have enough hydrogen on its surface for that hydrogen to begin to fuse to helium. It will do this very quickly and then ...
Photosphere
... Photosphere • Layer from which light escapes directly into space. • Photosphere is what we see. • Light from lower layers scatters. ...
... Photosphere • Layer from which light escapes directly into space. • Photosphere is what we see. • Light from lower layers scatters. ...
Benchmark lesson
... a lot of energy. Its energy comes from reaction between the hydrogen gas and the helium gas that makes up the Sun. During the reaction, called nuclear fusion, large amounts of energy are given off in the form of light and heat. Many schools and community buildings in Florida use this energy to heat ...
... a lot of energy. Its energy comes from reaction between the hydrogen gas and the helium gas that makes up the Sun. During the reaction, called nuclear fusion, large amounts of energy are given off in the form of light and heat. Many schools and community buildings in Florida use this energy to heat ...
Binary Orbits
... determine parameters e.g. period and line of sight velocities – masses – done in optical and X-ray • Fact that a large fraction of stars are found in binaries indicate stars are formed in groups through gravitational collapse of ...
... determine parameters e.g. period and line of sight velocities – masses – done in optical and X-ray • Fact that a large fraction of stars are found in binaries indicate stars are formed in groups through gravitational collapse of ...
Central Temperature and Density of Stars in Gravitational Equilibrium
... to hold between the pressure and density throughout the whole interior. Secondly, for a star having a shell structure our consideration is confined to its innermost homogeneous core. The pressure at the core boundary is assumed to be so small compared to the central pressure that the existence of th ...
... to hold between the pressure and density throughout the whole interior. Secondly, for a star having a shell structure our consideration is confined to its innermost homogeneous core. The pressure at the core boundary is assumed to be so small compared to the central pressure that the existence of th ...
Slide 1
... helium. At these temperatures most of the hydrogen is ionized, so the hydrogen lines are weak. Both HeI and HeII (singly ionized helium) are seen in the higher temperature examples. The radiation from O5 stars is so intense that it can ionize hydrogen over a volume of space 1000 light years across. ...
... helium. At these temperatures most of the hydrogen is ionized, so the hydrogen lines are weak. Both HeI and HeII (singly ionized helium) are seen in the higher temperature examples. The radiation from O5 stars is so intense that it can ionize hydrogen over a volume of space 1000 light years across. ...
Starlight & Stars - Wayne State University Physics and Astronomy
... of an object, unless it is moving at a significant fraction of the speed of light (VERY fast!) For an object moving toward us, the red colors will be shifted to the orange and the near-infrared will be shifted to the red, etc. All of the colors shift The overall color of the object depends on the co ...
... of an object, unless it is moving at a significant fraction of the speed of light (VERY fast!) For an object moving toward us, the red colors will be shifted to the orange and the near-infrared will be shifted to the red, etc. All of the colors shift The overall color of the object depends on the co ...
Evidence for the Big Bang
... a rushing to fill empty space The WHOLE universe is expanding - there is no empty space ...
... a rushing to fill empty space The WHOLE universe is expanding - there is no empty space ...
Oct 06, 2001
... B) It is the cloud from which protostars form C) It is a shell of gas ejected from a star late in its life. D) It is what is left when a white dwarf star explodes as a supernova. 8) What makes a high-mass star's core collapse? A) Energy from its outer layers compresses its core. B) The only thing t ...
... B) It is the cloud from which protostars form C) It is a shell of gas ejected from a star late in its life. D) It is what is left when a white dwarf star explodes as a supernova. 8) What makes a high-mass star's core collapse? A) Energy from its outer layers compresses its core. B) The only thing t ...
Northern Circumpolar Constellations
... Dipper) • Ursa Minor, the Little Bear • Cassiopeia, the Queen of Ethiopia • Cepheus, the King of Ethiopia • Draco the Dragon ...
... Dipper) • Ursa Minor, the Little Bear • Cassiopeia, the Queen of Ethiopia • Cepheus, the King of Ethiopia • Draco the Dragon ...
Section 1
... structure; but the structure (and hence the photospheric properties) changes with time, as the nuclear fuel powering the star is consumed. Hence the studies of stellar structure and of stellar evolution are inextricably linked. ...
... structure; but the structure (and hence the photospheric properties) changes with time, as the nuclear fuel powering the star is consumed. Hence the studies of stellar structure and of stellar evolution are inextricably linked. ...
New ultra faint dwarf galaxy candidates discovered with the Dark
... Dark Energy). This substance has been puzzling astronomers and physicists for 80 years now, and its nature is still unknown. **The ultimate nature of Dark Matter is a KEY UNSOLVED PROBLEM in basic physics today**, Just the sort of problem a fundamental science lab like Fermilab is interested in expl ...
... Dark Energy). This substance has been puzzling astronomers and physicists for 80 years now, and its nature is still unknown. **The ultimate nature of Dark Matter is a KEY UNSOLVED PROBLEM in basic physics today**, Just the sort of problem a fundamental science lab like Fermilab is interested in expl ...
PowerPoint version is here
... As Ye decreases, b- decay becomes important. Competition of EC and bstabilizes Ye near 0.45 When EC and b- compete we have the possibility of a cyclic process-the URCA process. ...
... As Ye decreases, b- decay becomes important. Competition of EC and bstabilizes Ye near 0.45 When EC and b- compete we have the possibility of a cyclic process-the URCA process. ...
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.