Ay 215: Physical Processes in Binary Stars

We now understand single stars quite well. The next frontier is binary stars. Some of the end points are of considerable interest to modern astronomy, for instance, gravitational waves: LIGO & LISA. Binarity results in a diversity of supernova explosions. The brightest stellar X-ray sources are due to binarity. Binarity produces strong UV sources in elliptical galaxies.This course is aimed at understanding the physical process in binary stars. These include mass loss, Roche lobe overflow, spin-up by angular momentum transfer, shrinkage of orbit due to loss of angular momentum from stellar winds, gravitational wave radiation. These processes will be discussed in the context of exotic stars such as double neutron stars, microquasars, blue stragglers and barium stars.

The class is based on “Physics of Binary Star Evolution” by Thomas M. Tauri & Edward P. J. van den Heuvel. Weekly homeworks will be assigned and the final exam is an oral exam.
Schedule: 10:30-12n, Tuesday & Thursday, Room 219, Cahill

A great astronomer is familiar with facts and at ease with physics. An observer must be able to compute the level of signal using facts and physics and must have knowledge of instruments to know if the signal is observable or not. A truly great astronomer should be able to do this whilst listening to a colloquium. Aspire!

Handy Formulae  |  Formulary

  1. The Algol Paradox & the mystery of blue stragglers.
    The common envelope phenomenon. presentation
    fun reading: Naming Variable Stars

  2. Introducing Cataclysmic Variables.
    presentation
    Classic papers: Paczysnki (1976)

  3. The period evolution of CVs.
    presentation
    Classic papers: Paczysnki (1981)  |  Paczysnki & Sienkiewicz (1981)

  4. Super-soft X-ray sources & Symbiotic stars.
    presentation
    Homework 1
    Classic papers: Nomoto (1982)

  5. Roche lobe
    presentation

  6. Dwarf Novae
    presentation

  7. X-ray binaries (intro)
    presentation

  8. X-ray binaries (cont)

  9. X-ray binaries, Short Period LMBH
    Short Period LMBH   |   presentation

  10. Mass Transfer
    Mass Transfer  |  presentation

  11. Student presentations I
    presentation

  12. Student presentations II
    presentation

  13. Mass Transfer (continued)
    presentation

  14. Introduction to SNe
    Perley SN  |  K Das (PhD)

  15. Evolution of single stars
    presentation

  16. Stellar Death, Helium stars. Common Envelope (iintro)
    presentation

  17. Common Envelope
    M31 2025abao (Karambelkar)  |  Darwin Instability

  18. Planetary Nebulae
    presentation