Astrophysics of Life - The Lives and Deaths of Stars

It gets cooler and fainter at the same radius what

Info icon This preview shows page 2. Sign up to view the full content.

View Full Document Right Arrow Icon
What eventually happens to a white dwarf? It gets cooler and fainter (at the same radius) What happens to higher mass stars? Gravity squeezes and heats the core enough to ignite Carbon Then Oxygen, then Neon . . . as each fuel gets exhausted in the core, its burning moves to a shell Concentric fusion shells form an “onion skin” structure Formation of an Iron core is the last stage Stars squiggle back and forth like crazy on HR diagram Why is iron formation the end of the line? Creating elements heavier than Iron requires energy With no more sources of energy, and Fe fusion taking energy from the gas, pressure support in the star’s core is lost . . . The core quickly collapses under its own weight . . . Protons and electrons are crushed together in the collapsing core, making neutrons Eventually, the neutrons are so close together they “touch” neutron degeneracy pressure (which is very stiff) The densities reach 100 billion kg/cm^3 (at those densities the whole Earth would fit in our football stadium!!) The collapsing neutron core then bounces! An explosive shock wave propagates outward, expelling all outer layers (Supernova) Crab nebula
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern