poll_questions
... White dwarf, neutron star, black hole All of three have about the same density ...
... White dwarf, neutron star, black hole All of three have about the same density ...
Letter to the Editor ASTRONOMY ASTROPHYSICS
... encounter of similarly massive disk galaxies. The remarkable slender tails would have been caused during a previous encounter that took place "' 7 x 10 8 years ago. Since the age of the stars that ionize the Hll nebulae at the tip of the stream is ~ 10 7 years, these stars were borned well after the ...
... encounter of similarly massive disk galaxies. The remarkable slender tails would have been caused during a previous encounter that took place "' 7 x 10 8 years ago. Since the age of the stars that ionize the Hll nebulae at the tip of the stream is ~ 10 7 years, these stars were borned well after the ...
The Distance Ladder I - Sierra College Astronomy Home Page
... Its luminosity is 4× greater than we thought. Its size is 2× greater than we thought. Its volume is 8× greater than we thought. Its mass (ρ×V) is 8× greater than we thought. If it is an energy source using fuel (mass) at a certain rate (luminosity), our estimate for its lifespan (mass/luminosity) wo ...
... Its luminosity is 4× greater than we thought. Its size is 2× greater than we thought. Its volume is 8× greater than we thought. Its mass (ρ×V) is 8× greater than we thought. If it is an energy source using fuel (mass) at a certain rate (luminosity), our estimate for its lifespan (mass/luminosity) wo ...
31 October: Supernovae and Neutron Stars
... Formation of a neutron star from stellar core • As core collapses, matter becomes compressed • Electrons and protons forced together e+p > n + nu (neutronization) • Core of the becomes a neutron fluid • Neutronization produces a burst of neutrinos • Neutron fluid in core becomes degenerate and rigi ...
... Formation of a neutron star from stellar core • As core collapses, matter becomes compressed • Electrons and protons forced together e+p > n + nu (neutronization) • Core of the becomes a neutron fluid • Neutronization produces a burst of neutrinos • Neutron fluid in core becomes degenerate and rigi ...
NASA`s Chandra Sees Brightest Supernova Ever
... is about 5 × 10−4 M⊙ yr−1. We find that it falls short of the circumstellar density that would be needed to power the visual light curve of SN 2006gy by three orders of magnitude. That account for why we observe a relatively weak and soft (i.e., unabsorbed) X-ray flux from SN 2006gy. In order to p ...
... is about 5 × 10−4 M⊙ yr−1. We find that it falls short of the circumstellar density that would be needed to power the visual light curve of SN 2006gy by three orders of magnitude. That account for why we observe a relatively weak and soft (i.e., unabsorbed) X-ray flux from SN 2006gy. In order to p ...
Evidence for an oscillation of the magnetic axis of the white dwarf in
... from about φ −0.36 to 0.19 and is caused by emission from the prime pole visible during this interval (Pandel et al. 2002; Schwope et al. 2002, and references therein). Cyclotron beaming is responsible for the double-humped shape. The flux in the phase interval, φ = 0.19–0.64, is cyclotron emissio ...
... from about φ −0.36 to 0.19 and is caused by emission from the prime pole visible during this interval (Pandel et al. 2002; Schwope et al. 2002, and references therein). Cyclotron beaming is responsible for the double-humped shape. The flux in the phase interval, φ = 0.19–0.64, is cyclotron emissio ...
The white dwarf cooling sequence of 47 Tucanae
... star to the coolest one, to experimentally determine the rate at which white dwarfs are cooling. They assumed a constant white dwarf formation rate. Thus, the position in the sorted list is proportional to the time spent on the cooling sequence. Their sorted, completeness-corrected distribution of e ...
... star to the coolest one, to experimentally determine the rate at which white dwarfs are cooling. They assumed a constant white dwarf formation rate. Thus, the position in the sorted list is proportional to the time spent on the cooling sequence. Their sorted, completeness-corrected distribution of e ...
1/2 - Indico
... volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star—over 97% of the stars in the Milky Way. After the hydrogen ...
... volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star—over 97% of the stars in the Milky Way. After the hydrogen ...
Life Cycle of stars
... By not emitting anymore light, the white dwarf star becomes a black dwarf star. Black dwarf stars usually have temperatures near absolute zero, and have diameters similar to that of terrestrial planets such as Earth and Venus. In this stage, the black dwarf star will remain forever emitting no ligh ...
... By not emitting anymore light, the white dwarf star becomes a black dwarf star. Black dwarf stars usually have temperatures near absolute zero, and have diameters similar to that of terrestrial planets such as Earth and Venus. In this stage, the black dwarf star will remain forever emitting no ligh ...
Characterizing the Cool KOIs
... Observatory" at Keck Observatory! 400 Massive, Evolved Stars 900 Sun-like dwarfs 150 Low-mass M dwarfs ! -‐ Each with 20+ HIRES spectra -‐ R ~ 55,000 -‐S/N ~ 200 ...
... Observatory" at Keck Observatory! 400 Massive, Evolved Stars 900 Sun-like dwarfs 150 Low-mass M dwarfs ! -‐ Each with 20+ HIRES spectra -‐ R ~ 55,000 -‐S/N ~ 200 ...
binary stars
... E = m c 2 Energy!!! • If the Sun had more mass, it would have more gravity, and its center would be under greater pressure. The greater the pressure, the greater the temperature, and the more violent the nuclear collisions. More fusion would occur, and more energy would be produced. This explains t ...
... E = m c 2 Energy!!! • If the Sun had more mass, it would have more gravity, and its center would be under greater pressure. The greater the pressure, the greater the temperature, and the more violent the nuclear collisions. More fusion would occur, and more energy would be produced. This explains t ...
Life Cycle of Stars
... temperature of a star determines its color – from cool, red stars to hot, blue ones. The Sun is a medium temperature yellow star. Around 1910, astronomers Ejnar Hertzsprung and Henry Russell independently developed what is now known as the Hertzsprung-Russell or H-R diagram. This graph plots the rel ...
... temperature of a star determines its color – from cool, red stars to hot, blue ones. The Sun is a medium temperature yellow star. Around 1910, astronomers Ejnar Hertzsprung and Henry Russell independently developed what is now known as the Hertzsprung-Russell or H-R diagram. This graph plots the rel ...
Wednesday, April 23 - Otterbein University
... Small, rapidly rotating objects Can’t be white dwarfs; must be neutron stars ...
... Small, rapidly rotating objects Can’t be white dwarfs; must be neutron stars ...
–1– 1. Polytropes – Derivation and Solutions of the Lane
... numerical integration) for the internal structure of a star that can be tabulated and used for estimates of various quantities. They are much simpler to manipulate than the full rigorous solutions of all the equations of stellar structure. But the price of this simplicity is assuming a power law rel ...
... numerical integration) for the internal structure of a star that can be tabulated and used for estimates of various quantities. They are much simpler to manipulate than the full rigorous solutions of all the equations of stellar structure. But the price of this simplicity is assuming a power law rel ...
Supernovae and compact objects
... very closely in a binary system. If they are sufficiently close, they will emit gravitational radiation as they orbit, which will remove energy from the orbit and cause them to eventually collide and merge. This is referred to as the double-degenerate scenario, since it involves two degenerate stars ...
... very closely in a binary system. If they are sufficiently close, they will emit gravitational radiation as they orbit, which will remove energy from the orbit and cause them to eventually collide and merge. This is referred to as the double-degenerate scenario, since it involves two degenerate stars ...
Cataclysmic Variables
... near 80 minutes is reached. After this point, the structure of the secondary again changes (becoming degenerate) and the orbital period increases. A cataclysmic variable is usually identified by its variability on timescales of minutes (from flickering) to hours (from orbital variations) to weeks- ...
... near 80 minutes is reached. After this point, the structure of the secondary again changes (becoming degenerate) and the orbital period increases. A cataclysmic variable is usually identified by its variability on timescales of minutes (from flickering) to hours (from orbital variations) to weeks- ...
Population synthesis of Be/white dwarf binaries in the Galaxy
... since they must have evolved from massive progenitors, perhaps close to the maximum mass for white dwarf progenitor stars, and they are likely themselves to be much more massive than the mean for white dwarfs in general (0.57 M , Finley et al. 1997). The presence of a component of spectral class B ...
... since they must have evolved from massive progenitors, perhaps close to the maximum mass for white dwarf progenitor stars, and they are likely themselves to be much more massive than the mean for white dwarfs in general (0.57 M , Finley et al. 1997). The presence of a component of spectral class B ...
Testing the evolution of the DB white dwarf GD 358: first results of a
... range 4.8 to 10.3 M lose the hydrogen-rich matter in two episodes of Roche-lobe overflow and become C/O degenerate dwarfs with masses in the range 0.7 to 1.08 M . This channel leads to the production of DB white dwarfs. For the more massive remnants (over 0.8 M ), a substantial part of the helium ...
... range 4.8 to 10.3 M lose the hydrogen-rich matter in two episodes of Roche-lobe overflow and become C/O degenerate dwarfs with masses in the range 0.7 to 1.08 M . This channel leads to the production of DB white dwarfs. For the more massive remnants (over 0.8 M ), a substantial part of the helium ...
The white dwarf cooling sequence of 47 Tucanae
... pronounced break at effective temperatures T eff = 20 000 K. This feature remained unexplained in Goldsbury et al. (2012) – see their Fig. 10 – and prompted them to attribute its origin to some missing piece of physics in all the existing models at moderate temperatures. The results of our population ...
... pronounced break at effective temperatures T eff = 20 000 K. This feature remained unexplained in Goldsbury et al. (2012) – see their Fig. 10 – and prompted them to attribute its origin to some missing piece of physics in all the existing models at moderate temperatures. The results of our population ...
astrophysics - Uplift Summit Intl
... (c) Explain, by reference to the Chandrasekhar limit, why the final stage of the evolutionary path of the Sun is at F. White dwarfs are found in region F of the HR diagram. Main sequence stars that end up with a mass under the Chandrasekhar limit of 1.4 solar masses will become white dwarfs. (d) On ...
... (c) Explain, by reference to the Chandrasekhar limit, why the final stage of the evolutionary path of the Sun is at F. White dwarfs are found in region F of the HR diagram. Main sequence stars that end up with a mass under the Chandrasekhar limit of 1.4 solar masses will become white dwarfs. (d) On ...
Modeling White Dwarf Star Magnetization - Blogs at H-SC
... generate high pressure that can prevent the stars from collapsing by the gravity. When the nuclear fusion ends, main sequence stars with small mass proceed to a giant phase which fuses next level of the elements. When stars cannot continue their nuclear fusions, their outer layers explode. After the ...
... generate high pressure that can prevent the stars from collapsing by the gravity. When the nuclear fusion ends, main sequence stars with small mass proceed to a giant phase which fuses next level of the elements. When stars cannot continue their nuclear fusions, their outer layers explode. After the ...
Neutron Stars and Pulsars
... • A black hole with a visible companion will be a strong source of xrays. The x-ray emission intensity should exhibit rapid fluctuations because of the chaotic nature of the processes that cause the x-ray emission. • So, we search for binary systems in which (a) one of the objects is visible, (b) th ...
... • A black hole with a visible companion will be a strong source of xrays. The x-ray emission intensity should exhibit rapid fluctuations because of the chaotic nature of the processes that cause the x-ray emission. • So, we search for binary systems in which (a) one of the objects is visible, (b) th ...
Sources with
... A theory of star formation requires to explain the origins of stars over four orders of magnitude in mass ...
... A theory of star formation requires to explain the origins of stars over four orders of magnitude in mass ...