Astronomy and Survey of Information
... • It is impossible to obtain the complete orbit of a spectroscopic binary unless it is also a visual or an eclipsing binary, so from these objects only a determination of the joint product of mass and the sine of the angle of inclination relative to the line of sight is possible. • Therefore, withou ...
... • It is impossible to obtain the complete orbit of a spectroscopic binary unless it is also a visual or an eclipsing binary, so from these objects only a determination of the joint product of mass and the sine of the angle of inclination relative to the line of sight is possible. • Therefore, withou ...
Measuring the Masses of Neutron Stars
... first. When it starts to become a supergiant, it starts overflowing its Roche lobe, so that the companion 9 M A star will receive mass and becomes a 16 M A star (i.e. the current mass of the B supergiant companion to SMC X-1, neglecting the mass that the supergiant has lost due to its stellar wind). ...
... first. When it starts to become a supergiant, it starts overflowing its Roche lobe, so that the companion 9 M A star will receive mass and becomes a 16 M A star (i.e. the current mass of the B supergiant companion to SMC X-1, neglecting the mass that the supergiant has lost due to its stellar wind). ...
Supernovae and Gamma-Ray Bursts (draft)
... The second important explosion mechanism has nothing to do with massive stars, but is generally believed to occur in accreting CO white dwarfs when their mass approaches the Chandrasekhar mass. When the mass reaches ∼ 1.37 M⊙, carbon is ignited in or near the centre of the white dwarf. Initially, th ...
... The second important explosion mechanism has nothing to do with massive stars, but is generally believed to occur in accreting CO white dwarfs when their mass approaches the Chandrasekhar mass. When the mass reaches ∼ 1.37 M⊙, carbon is ignited in or near the centre of the white dwarf. Initially, th ...
Photometry
... main sequence on your paper graph. Keep the y axes precisely parallel and over top one another. Seek a best fit for the central portion of the combined patterns. (The cool red stars in the lower right of your paper graph are quite scattered and may not fit very well.) Each star of the main sequence ...
... main sequence on your paper graph. Keep the y axes precisely parallel and over top one another. Seek a best fit for the central portion of the combined patterns. (The cool red stars in the lower right of your paper graph are quite scattered and may not fit very well.) Each star of the main sequence ...
Stars and Constellations
... pulling gas molecules toward its center. Gravity is counteracted by the pressure of the hot gas inside the center of the star. Gravity pulls inward, and the pressure pushes outward. The two forces balance each other and the star maintains a spherical shape. This balance is called hydrostatic support ...
... pulling gas molecules toward its center. Gravity is counteracted by the pressure of the hot gas inside the center of the star. Gravity pulls inward, and the pressure pushes outward. The two forces balance each other and the star maintains a spherical shape. This balance is called hydrostatic support ...
Weighing a Black Hole
... supermassive black holes, if, by definition, we can't see black holes since not even light can escape from them? The supermassive black holes at the centers of galaxies are thought to have masses between hundreds of thousands to tens of billions times the mass of our Sun. Because of these tremendous ...
... supermassive black holes, if, by definition, we can't see black holes since not even light can escape from them? The supermassive black holes at the centers of galaxies are thought to have masses between hundreds of thousands to tens of billions times the mass of our Sun. Because of these tremendous ...
HOW TO MAKE A SINGLETON sdB STAR VIA ACCELERATED STELLAR... Drew Clausen and Richard A. Wade
... concentrated in mass at the usual He ignition mass at the tip of the RGB, 0.47–0.51 M , which would account for the observed narrow mass distribution of singleton sdBs with precise mass determinations. The problem is that the universe is not yet old enough for this to have occurred in the single st ...
... concentrated in mass at the usual He ignition mass at the tip of the RGB, 0.47–0.51 M , which would account for the observed narrow mass distribution of singleton sdBs with precise mass determinations. The problem is that the universe is not yet old enough for this to have occurred in the single st ...
3-D Visualization of Cataclysmic Variables With IDL by:
... toward the white dwarf. In some systems, especially those where the magnetic field of the white dwarf is not very strong, the gas doesn’t actually fall directly into the white dwarf but encircles it and forms a disc. This disc, known as an accretion disc with the white dwarf serving as its center, ...
... toward the white dwarf. In some systems, especially those where the magnetic field of the white dwarf is not very strong, the gas doesn’t actually fall directly into the white dwarf but encircles it and forms a disc. This disc, known as an accretion disc with the white dwarf serving as its center, ...
No Slide Title
... 7. The nebulae around protostars are shaped into disks because of the same process that causes dough to become flat when it is a) spun in the air like pizza dough b) rolled with a pin like pizza dough c) squashed between plates like dough for a burrito d) baked on a flat sheet like a cookie. ...
... 7. The nebulae around protostars are shaped into disks because of the same process that causes dough to become flat when it is a) spun in the air like pizza dough b) rolled with a pin like pizza dough c) squashed between plates like dough for a burrito d) baked on a flat sheet like a cookie. ...
Stellar Masses
... mass (10%) is involved in nuclear burning regardless of mass, and so the relative main-sequence lifetime τms will be roughly proportional to the mass (the amount of fuel) and inversely proportional to the luminosity (how quickly the fuel is consumed), i.e. τms ~ M/L. Given the mass– luminosity relat ...
... mass (10%) is involved in nuclear burning regardless of mass, and so the relative main-sequence lifetime τms will be roughly proportional to the mass (the amount of fuel) and inversely proportional to the luminosity (how quickly the fuel is consumed), i.e. τms ~ M/L. Given the mass– luminosity relat ...
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. ...
Core Collapse Supernovae and Neutron Star Kicks, a Primer David
... asymmetry are Hydrodynamically driven kicks and Neutrino-magnetic field driven kicks. Conversely, the kick could come as a push after the neutron star is formed since pulsars are observed to emit in a preferred direction. This method is referred to as the Electromagnetic rocket. Hydrodynamically dri ...
... asymmetry are Hydrodynamically driven kicks and Neutrino-magnetic field driven kicks. Conversely, the kick could come as a push after the neutron star is formed since pulsars are observed to emit in a preferred direction. This method is referred to as the Electromagnetic rocket. Hydrodynamically dri ...
ChESS: ChaMP Extended Stellar Survey
... We have systemati ally sear hed for opti al mat hes to X-ray sour es from the Chandra Multi-wavelength Proje t (ChaMP; Green et al. 2004) using the Ty ho, GSC, SDSS, and ChaMP opti al follow-up atalogs. We nd over 200 stellar X-ray sour es overing a magnitude range V = 10 19. This forms an X-ray ...
... We have systemati ally sear hed for opti al mat hes to X-ray sour es from the Chandra Multi-wavelength Proje t (ChaMP; Green et al. 2004) using the Ty ho, GSC, SDSS, and ChaMP opti al follow-up atalogs. We nd over 200 stellar X-ray sour es overing a magnitude range V = 10 19. This forms an X-ray ...
SALT Science – UW Madison
... The goal of this work is to understand connections between galaxies and the supermassive black holes at their centers, in the context of galaxy formation and evolution. We study this through the properties of luminous quasar host galaxies, objects in which the galaxy is actively feeding its black ho ...
... The goal of this work is to understand connections between galaxies and the supermassive black holes at their centers, in the context of galaxy formation and evolution. We study this through the properties of luminous quasar host galaxies, objects in which the galaxy is actively feeding its black ho ...
A PLANET IN AN 840 DAY ORBIT AROUND A KEPLER MAIN
... The minimum mass of the sub-stellar companion to KIC 7917485 (11.8 M Jup ) is close to the planet–brown-dwarf mass boundary. Although such a body would not be expected to have a solid surface, it could presumably host smaller exomoons. It is therefore interesting to determine whether the planet lies ...
... The minimum mass of the sub-stellar companion to KIC 7917485 (11.8 M Jup ) is close to the planet–brown-dwarf mass boundary. Although such a body would not be expected to have a solid surface, it could presumably host smaller exomoons. It is therefore interesting to determine whether the planet lies ...
neutron star - Chabot College
... • Contrast X-ray bursters with novae on white dwarfs. • Novae occur when hydrogen fusion suddenly ignites on the surface of a white dwarf in a binary system. In contrast, hydrogen fusion is steady on the surface of a neutron star in a binary system. However, the steady hydrogen burning builds up a l ...
... • Contrast X-ray bursters with novae on white dwarfs. • Novae occur when hydrogen fusion suddenly ignites on the surface of a white dwarf in a binary system. In contrast, hydrogen fusion is steady on the surface of a neutron star in a binary system. However, the steady hydrogen burning builds up a l ...
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.