Black Holes and Relativity (Professor Powerpoint)
... are observed quite frequently with the Hubble Telescope. •In many cases, the amount of matter needed to make the gravitational lens is much more than can be accounted for by the visible matter. ...
... are observed quite frequently with the Hubble Telescope. •In many cases, the amount of matter needed to make the gravitational lens is much more than can be accounted for by the visible matter. ...
Classification_of_Stars_By_Luminosity
... Apparent magnitude • Apparent magnitude is not necessarily related to the amount of light actually produced by the star but is simply a measure of how bright it appears to be from Earth. • (Some bright stars are simply close neighbours while other giant stars may appear equally bright but are also ...
... Apparent magnitude • Apparent magnitude is not necessarily related to the amount of light actually produced by the star but is simply a measure of how bright it appears to be from Earth. • (Some bright stars are simply close neighbours while other giant stars may appear equally bright but are also ...
Slide 1
... 6. Uncertainties in evolutionary tracks, isochrones;Teff scale: especially for very young clusters (PMS stars) and low-mass stars, but to some extent for all cluster studies. Coupled to 5 above. Nearly all these uncertainties increase with cluster distance. Note that effects of 2 and 4 are to gi ...
... 6. Uncertainties in evolutionary tracks, isochrones;Teff scale: especially for very young clusters (PMS stars) and low-mass stars, but to some extent for all cluster studies. Coupled to 5 above. Nearly all these uncertainties increase with cluster distance. Note that effects of 2 and 4 are to gi ...
Summary of Astronomy
... • Nuclear furnace goes out when runs out of fuel • H->He->O->…->Fe • Star core fusion produces energy until it starts to burn Fe . . . Now it requires energy! • The core no longer can win against gravity • Star collapses into the core • Rebounds • Spews elements 1-92 into space ...
... • Nuclear furnace goes out when runs out of fuel • H->He->O->…->Fe • Star core fusion produces energy until it starts to burn Fe . . . Now it requires energy! • The core no longer can win against gravity • Star collapses into the core • Rebounds • Spews elements 1-92 into space ...
Recent science results from VLTI commissioning
... but ~30 x 106 L at outburst (2nd brightest object in sky) • Super hot: 15-40 x 103 K • Super active: survivor of 1843 eruption that created the homunculus and expelled ~ 2-3M at up to 800 km/s • Current rate of mass loss 0.3-3 x 10-3 M/yr • Central object is not viewed directly but is obscured by ...
... but ~30 x 106 L at outburst (2nd brightest object in sky) • Super hot: 15-40 x 103 K • Super active: survivor of 1843 eruption that created the homunculus and expelled ~ 2-3M at up to 800 km/s • Current rate of mass loss 0.3-3 x 10-3 M/yr • Central object is not viewed directly but is obscured by ...
UMich w/s
... Characteristic Density ~10GeV/c²/cm³ If DM is very massive particles, they must be ...
... Characteristic Density ~10GeV/c²/cm³ If DM is very massive particles, they must be ...
Why the Model of a Hydrogen
... such as hydrogen and helium. He proposed an abundance table based on the solar atmosphere. Hoyle5 maintained, however, that the results of Payne2 and Russell3 were for the atmospheres, not for the deep interiors of stars. He, Eddington, and other astronomers continued to believe until the end of Wor ...
... such as hydrogen and helium. He proposed an abundance table based on the solar atmosphere. Hoyle5 maintained, however, that the results of Payne2 and Russell3 were for the atmospheres, not for the deep interiors of stars. He, Eddington, and other astronomers continued to believe until the end of Wor ...
The Milky Way and Its Neighbors
... Ellipticals appear to have very little gas or dust Approximately 10% of known galaxies are elliptical Stars orbit the galaxy center in all different planes Circular orbital velocity measurements do not work very well Sometimes a preferred direction of very slow rotation Luminosity decrea ...
... Ellipticals appear to have very little gas or dust Approximately 10% of known galaxies are elliptical Stars orbit the galaxy center in all different planes Circular orbital velocity measurements do not work very well Sometimes a preferred direction of very slow rotation Luminosity decrea ...
Neutrino Physics M. SPURIO University of Bologna and INFN
... Stars with masses above eight solar masses undergo gravitational collapse. Once the core of the star becomes constituted primarily of iron, further compression of the core does not ignite nuclear fusion and the star is unable to thermodynamically support its outer envelope. As the surrounding ...
... Stars with masses above eight solar masses undergo gravitational collapse. Once the core of the star becomes constituted primarily of iron, further compression of the core does not ignite nuclear fusion and the star is unable to thermodynamically support its outer envelope. As the surrounding ...
Archaeology of the Milky Way - Max-Planck
... a well like marbles, and the gas compacted to form the first stars and galaxies. Without the midwifery of the dark matter, there would probably be no galaxies or stars. According to the conventional school of thought, the large galaxies like our Milky Way didn’t form to full size. Rather, there were ...
... a well like marbles, and the gas compacted to form the first stars and galaxies. Without the midwifery of the dark matter, there would probably be no galaxies or stars. According to the conventional school of thought, the large galaxies like our Milky Way didn’t form to full size. Rather, there were ...
5 Report of the Panel on Stars and Stellar Evolution
... stellar phenomena, leading to a number of breakthrough discoveries. Newly discovered radio pulsars in binaries, including the unique double pulsar system, provide some of the most stringent tests of general relativity. Advances in X-ray astronomy have led to new discoveries related to accreting neut ...
... stellar phenomena, leading to a number of breakthrough discoveries. Newly discovered radio pulsars in binaries, including the unique double pulsar system, provide some of the most stringent tests of general relativity. Advances in X-ray astronomy have led to new discoveries related to accreting neut ...
astro-ph/0502206 PDF
... b) Why is the ratio of Oxygen atoms to Carbon atoms only 2 at the Sun’s surface, when laboratory and theoretical calculations predict a much higher value ? c) If fusion powers the Sun, why does it discard 50 trillion tons of Hydrogen each year as “solar wind” trash, with traces of other elements car ...
... b) Why is the ratio of Oxygen atoms to Carbon atoms only 2 at the Sun’s surface, when laboratory and theoretical calculations predict a much higher value ? c) If fusion powers the Sun, why does it discard 50 trillion tons of Hydrogen each year as “solar wind” trash, with traces of other elements car ...
Equations of State for White Dwarfs Elena Heikkilä Kandidaatin
... Most observed white dwarfs have relatively high surface temperatures, between 8, 000 K and 40, 000 K [2]. The surface temperature of ∼ 104 K implies a white color [3]. White dwarfs are classified as compact objects, meaning that their life begins when a star dies. Star death is a point where the mos ...
... Most observed white dwarfs have relatively high surface temperatures, between 8, 000 K and 40, 000 K [2]. The surface temperature of ∼ 104 K implies a white color [3]. White dwarfs are classified as compact objects, meaning that their life begins when a star dies. Star death is a point where the mos ...
Two extremely luminous WN stars in the Galactic center with
... and contains many OB-type stars, the more evolved Quintuplet cluster (3–5 Myr old) harbors many Wolf-Rayet (WR) stars. Besides these compact stellar conglomerates, many high-mass stars whose association with stellar clusters is not obvious are scattered in the GC. Among these are the rather isolated ...
... and contains many OB-type stars, the more evolved Quintuplet cluster (3–5 Myr old) harbors many Wolf-Rayet (WR) stars. Besides these compact stellar conglomerates, many high-mass stars whose association with stellar clusters is not obvious are scattered in the GC. Among these are the rather isolated ...
Question 9: Starting from the ground state, press two and only two
... with other atoms. For example, the energy levels of a single carbon atom are slightly different than a diamond. Similarly, hydrogen gas (H2) is a tiny bit different than a simple H atom. The difference in energy levels, however, is not much in that case. The Hydrogen Atom Simulator showed just one H ...
... with other atoms. For example, the energy levels of a single carbon atom are slightly different than a diamond. Similarly, hydrogen gas (H2) is a tiny bit different than a simple H atom. The difference in energy levels, however, is not much in that case. The Hydrogen Atom Simulator showed just one H ...
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.