The Triple-Ring Nebula: Fingerprint of a Binary Merger
... it heats up the envelope causing the ejection of part of the envelope (typically ejecting half a solar mass of material). Because of the disk-like structure of the envelope, matter is more easily ejected along the polar direction. Indeed in the best models, no mass is ejected in the plane of the dis ...
... it heats up the envelope causing the ejection of part of the envelope (typically ejecting half a solar mass of material). Because of the disk-like structure of the envelope, matter is more easily ejected along the polar direction. Indeed in the best models, no mass is ejected in the plane of the dis ...
Sec 29.3 - Highland High School
... Internal pressure in white dwarfs A white dwarf is stable despite its lack of nuclear reactions because it is supported by the resistance of electrons being squeezed together. This pressure counteracts gravity and can support the core as long as the mass of the remaining core is less than about 1.4 ...
... Internal pressure in white dwarfs A white dwarf is stable despite its lack of nuclear reactions because it is supported by the resistance of electrons being squeezed together. This pressure counteracts gravity and can support the core as long as the mass of the remaining core is less than about 1.4 ...
Mass-radius Relations for Helium White Dwarfs
... emission, that is M-R relations of the fully degenerate helium WDs for masses greater than 0.4 M are presented. Figure 1. shows the M-R relations for helium WDs calculated by Hamada and Salpeter [5], Althaus and Benvenuto [1], Vennes et al. [11] and our results. In this figure, plus sign shows our ...
... emission, that is M-R relations of the fully degenerate helium WDs for masses greater than 0.4 M are presented. Figure 1. shows the M-R relations for helium WDs calculated by Hamada and Salpeter [5], Althaus and Benvenuto [1], Vennes et al. [11] and our results. In this figure, plus sign shows our ...
A Disintegrating Minor Planet Transiting a White
... atmospheres are similar to rocky bodies in the Solar system6,7. This and the existence of warm dusty debris disks8–13 around about 4% of white dwarfs14–16 suggest that rocky debris from white dwarf progenitors’ planetary systems occasionally pollute the stars’ atmospheres 17 . The total accreted mas ...
... atmospheres are similar to rocky bodies in the Solar system6,7. This and the existence of warm dusty debris disks8–13 around about 4% of white dwarfs14–16 suggest that rocky debris from white dwarf progenitors’ planetary systems occasionally pollute the stars’ atmospheres 17 . The total accreted mas ...
A Disintegrating Minor Planet Transiting a White Dwarf
... atmospheres are similar to rocky bodies in the Solar system6,7. This and the existence of warm dusty debris disks8–13 around about 4% of white dwarfs14–16 suggest that rocky debris from white dwarf progenitors’ planetary systems occasionally pollute the stars’ atmospheres 17 . The total accreted mas ...
... atmospheres are similar to rocky bodies in the Solar system6,7. This and the existence of warm dusty debris disks8–13 around about 4% of white dwarfs14–16 suggest that rocky debris from white dwarf progenitors’ planetary systems occasionally pollute the stars’ atmospheres 17 . The total accreted mas ...
Chapter 21 Notes
... • A nova is a star that suddenly brightens and gradually fades; it is a white dwarf whose larger partner continually transfers material to it. • Stars greater than eight solar masses can have fusion in their cores going all the way up to iron, which is stable ...
... • A nova is a star that suddenly brightens and gradually fades; it is a white dwarf whose larger partner continually transfers material to it. • Stars greater than eight solar masses can have fusion in their cores going all the way up to iron, which is stable ...
Globular cluster absolute ages from cooling brown dwarfs
... In order to probe the evolution of brown dwarfs, we ran a suite of models (Paxton et al. 2011) for different initial masses and the metal content of the globular cluster 47 Tucanae. The specifications of our models are explained in Appendix A. From the models, we can see that in the early stages of ...
... In order to probe the evolution of brown dwarfs, we ran a suite of models (Paxton et al. 2011) for different initial masses and the metal content of the globular cluster 47 Tucanae. The specifications of our models are explained in Appendix A. From the models, we can see that in the early stages of ...
Powerpoint
... In fact, except for a thin region near their surfaces, such stars will be entirely convective and will have a total binding energy that approaches zero as approaches zero. But the calculation applies to those surface layers which must stay bound. Completely convective stars with a luminosity propo ...
... In fact, except for a thin region near their surfaces, such stars will be entirely convective and will have a total binding energy that approaches zero as approaches zero. But the calculation applies to those surface layers which must stay bound. Completely convective stars with a luminosity propo ...
On the possibility of a helium white dwarf donor in the presumed
... As noted by Juett et al. (2003) and Nelemans et al. (2004), there is a puzzling contradiction between the characteristics (or mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred sec ...
... As noted by Juett et al. (2003) and Nelemans et al. (2004), there is a puzzling contradiction between the characteristics (or mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred sec ...
The origin of the strongest magnetic fields in dwarfs
... mass is 1.44M . Because all adjacent momentum states are filled there are few states into which any electron can be scattered. This means that they have a long mean free path and the white dwarf is isothermal. There is very little resistance to current flow and so it also appears superconducting an ...
... mass is 1.44M . Because all adjacent momentum states are filled there are few states into which any electron can be scattered. This means that they have a long mean free path and the white dwarf is isothermal. There is very little resistance to current flow and so it also appears superconducting an ...
Dynamical Properties of Infrared Dark Clouds
... Figure 4: (Left) A face on plot of the Galactic IRDCs [Northern: 13CO Simon et al. 2006b; Southern, this work]. The positions of the Sun and Galactic Center are marked. Comparing this to a two-armed model of the Milky Way’s spiral arms (right, courtesy of B. Benjamin), it can be seen that the IRDC d ...
... Figure 4: (Left) A face on plot of the Galactic IRDCs [Northern: 13CO Simon et al. 2006b; Southern, this work]. The positions of the Sun and Galactic Center are marked. Comparing this to a two-armed model of the Milky Way’s spiral arms (right, courtesy of B. Benjamin), it can be seen that the IRDC d ...
Stellar Temperatures
... measure. However, it is relatively simple to measure the relative brightness of one star to another. Therefore one always measures magnitudes relative to stars with previously assigned magnitudes. The most common zero points are • Vega-based magnitudes: the star α Lyr is assigned m = 0 • AB-magnit ...
... measure. However, it is relatively simple to measure the relative brightness of one star to another. Therefore one always measures magnitudes relative to stars with previously assigned magnitudes. The most common zero points are • Vega-based magnitudes: the star α Lyr is assigned m = 0 • AB-magnit ...
UvA-DARE (Digital Academic Repository)
... withh B12 the magnetic field strength in units of 10 12 Gauss and P in units of 1 0 - 1 5 s/s. Ass pulsars grow older, their rotation slows down and their fields may decrease in strength. Eventuallyy the polar cap voltage falls below a certain value, the pulsar switches off: it 'dies'. A nn often us ...
... withh B12 the magnetic field strength in units of 10 12 Gauss and P in units of 1 0 - 1 5 s/s. Ass pulsars grow older, their rotation slows down and their fields may decrease in strength. Eventuallyy the polar cap voltage falls below a certain value, the pulsar switches off: it 'dies'. A nn often us ...
L103 A NEW MILKY WAY DWARF SATELLITE IN CANES
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
Stellar Evolution and the fate of the Solar System
... YUV420 codec decompressor are needed to see this picture. ...
... YUV420 codec decompressor are needed to see this picture. ...
Massive star formation in 100000 years from turbulent and
... ends up in the star: m∗f = ǫcore Mcore , where m∗f is the final stellar mass (for binary and other multiple star systems, m∗f is the total mass of stars in the system). To estimate ǫcore for massive stars, we assume that their outflows are scaled versions of the outflows from low-mass stars, which i ...
... ends up in the star: m∗f = ǫcore Mcore , where m∗f is the final stellar mass (for binary and other multiple star systems, m∗f is the total mass of stars in the system). To estimate ǫcore for massive stars, we assume that their outflows are scaled versions of the outflows from low-mass stars, which i ...
Lecture 7 Evolution of Massive Stars on the Main Sequence and
... Because of the general tendency of the interior temperature of main sequence stars to increase with mass, stars of over two solar mass are chiefly powered by the CNO cycle(s) rather than the pp cycle(s). This, plus the increasing fraction of pressure due to radiation, makes their cores convective. T ...
... Because of the general tendency of the interior temperature of main sequence stars to increase with mass, stars of over two solar mass are chiefly powered by the CNO cycle(s) rather than the pp cycle(s). This, plus the increasing fraction of pressure due to radiation, makes their cores convective. T ...
First Light: Physical Characterization of Early Star Formation in the
... 2. Broadening our Perspective: the Dwarfs, M31, and Cen A The Milky Way has shaped the modern view that galaxies form hierarchically through the merging of clumps of gas and stars, accompanied by slower accretion of gas. In this picture, dwarf galaxies may represent protogalactic fragments that hav ...
... 2. Broadening our Perspective: the Dwarfs, M31, and Cen A The Milky Way has shaped the modern view that galaxies form hierarchically through the merging of clumps of gas and stars, accompanied by slower accretion of gas. In this picture, dwarf galaxies may represent protogalactic fragments that hav ...
Document
... If the situation leads to accretion onto a relatively normal star with R ~ R, or even onto a white dwarf, the energy liberated is not particularly high. However for small radii, such as a neutron star where R ~ 104 m, and M ~ 1.4 M then we find that > 20% of the rest mass energy is liberated as th ...
... If the situation leads to accretion onto a relatively normal star with R ~ R, or even onto a white dwarf, the energy liberated is not particularly high. However for small radii, such as a neutron star where R ~ 104 m, and M ~ 1.4 M then we find that > 20% of the rest mass energy is liberated as th ...
Interstellar Astrophysics Summary notes: Part 5
... found that MJ is proportional to T 3/2 ρ−0.5 . For typical values of T and ρ, one finds that MJ ∼ 105 M . Thus for the normal diffuse ISM, the Jeans’ mass is very large (105 = 100 000 M ). Since stars have masses of typically only a few solar masses, this implies that a large collapsing gas cloud ...
... found that MJ is proportional to T 3/2 ρ−0.5 . For typical values of T and ρ, one finds that MJ ∼ 105 M . Thus for the normal diffuse ISM, the Jeans’ mass is very large (105 = 100 000 M ). Since stars have masses of typically only a few solar masses, this implies that a large collapsing gas cloud ...
Lecture 24, The local group
... process. The MW dSph formed in such objects with M > 109 M , so were able to build up some stellar mass and survive reionization despite their present shallow potential wells .... This would make some concrete predictions about the age of the stars.. ...
... process. The MW dSph formed in such objects with M > 109 M , so were able to build up some stellar mass and survive reionization despite their present shallow potential wells .... This would make some concrete predictions about the age of the stars.. ...