White dwarf Definition and 62 Threads

Homework Statement After a star like the Sun has exhausted most of the hydrogen in its core it expands and cools to form a red giant. Eventually, when it has exhausted all its nuclear fuel, it sheds its outer layers and contracts and becomes a white dwarf of similar size to the Earth as...

Homework Statement In about 5 billion years, at the end of its lifetime, our sun will end up as a white dwarf, having about the same mass as it does now, but reduced to about 15,000 km in diameter.What will be its density at that stage? g/cm^3 Homework Equations D=m/v 4/3(3.14)r^3...

It's well known that white dwarf stars are supported by degenerate-electron pressure. Calculation shows that maximum mass of white dwarf star is about 1.4 solar mass. My question is why it has a maximum mass? The postulate of Quantum mechanics says that it should be a distribution of mass...

Homework Statement The Sun rotates about its own axis once every 26.0 days. Its mass is m_sun = 2.0E30 kg and radius is r_sun = 7.0E8 m. Assume that the Sun is a solid sphere with uniform density. Astrophysicists predict that the Sun will collapse into a white dwarf in some billions of...

Perhaps this should be on the homework forum but I'm not sure, so I put it here. How do you calculate the cooling time scale of the surface of a white dwarf and the surface of the core of a white dwarf? I have an equation for the cooling scale of a white dwarf in general but I'm not sure how...

Hi, Let's say we have a white dwarf accreting material from a giant partner. How long would it typically take for the white dwarf to go supernova? Is it of the order of a thousand years? A million? Any references would be much appreciated. Thanks, San

http://news.yahoo.com/s/nm/20070816/sc_nm/space_dwarf_dc;_ylt=AlGS1eXRs8GTnZf2V8LFS04hANEA Interesting possibilities! :cool: http://arxiv.org/abs/astro-ph/0509193 A Dusty Disk Around GD 362, a White Dwarf With a Uniquely High Photospheric Metal Abundance...

It is my general understanding that once a star goes supernova, the remnant core of the dead star will (always?) gravitationally contract into either a neutron star, or if massive enough, into a black hole. However, does current observation/model rule out a scenario whereupon a star goes...

I read in the book of world records that there are massive diamonds inside of some white dwarves. If this is compleatly true then how long after it's formation could a white dwarf start producing this massive diamond in it's core?

In the future when the sun ejects its outer layers as it becomes a white dwarf would there be enough ejected matter flying around the solar system to allow Jupiter to gain the required mass to become a star.

have solved the lane - emden eqn numerically for scaled radius, and the derivative of scaled pressure with respect of scaled radius, are given the eqn of state, n, and mass, how would i go about working out the central density and the radius? thanks

I have no idea. And how is the pressure/force/intensity of gravitational collapse known?