Credit: P. Marenfeld

Interacting Binaries

Seminar in Theoretical Astrophysics
Caltech Astronomy Course Ay 215, Winter Term 2009/2010

Instructor: Christian Ott


Ay 215, Seminar in Theoretical Astrophysics, is a course for graduate students and seniors in Astronomy, Physics, and Geophysics and Planetary Sciences. The goal of this course is to provide an overview of current topics and research in an area of (theoretical) astrophysics that is not typically comprehensively covered in standard courses.

This year, the focus will be on interacting binary stars. These systems are ubiquitous and come in many different kinds (e.g., close main-sequence binaries, white-dwarf -- white-dwarf binaries, neutron-star -- white-dwarf binaries, binaries in common-envelope phases and many others). Theoretical understanding, tested by observations, of binary interactions allows us to get a better grasp not only of stellar astrophysics, but also of more fundamental physics (e.g., the measurement of the event horizon radius and black-hole spin through observations of HMXBs). We will address interacting binaries broadly and cover as much as possible of the ensemble of close binary systems from their underlying (astro)physics to cutting-edge research. Despite the course title, the content will not be purely theoretical. Rather, it will be at the interface of theory and observation, contrasting model with reality.

Class Format:

The format will be a mixture of presentation, discussion, and step-by-step going through selected important papers.

We will meet at the beginning of the term for an introductory and overview meeting. There, each participant will pick a special topic (e.g., a particular kind of interaction process or type of binary system) and a class meeting date on which they will be the discussion leader. Being discussion leader will entail (i) a literature search and the selection of one or multiple key papers for in-depth discussion, (ii) preparing a 30-minute introductory presentation (format rather open), (iii) leading the class discussion on the topic, and (iv) preparing a max 5-page write-up, summarizing the most salient aspects of the topic. I will work with discussion leaders and will provide guidance for (i)-(iv).

A typical class meeting will start out with a 30-minute introductory presentation followed by ~1.5 hours of discussion and detailed, step-by-step study of one or multiple key papers selected by the discussion lead. All participants will be required to read the selected paper(s) and be ready for presenting/discussing it/them in detail on the blackboard or with the projector. In each meeting, one participant will be chosen to do this (of course, with the help of the others).

As mentioned above, each discussion leader will provide the class with a max. 5-page handout summarizing their special topic and a (if necessary, multi-page) literature list of key papers. These summaries will be collected and combined to a PDF booklet as a record of the course and for future reference.

Location:Cahill 304
Day, time, duration: We'll meet once a week on Tuesdays, 14:00 - 16:00 (2 pm - 4 pm).
First class meeting:01/05/2010
Impact:2 hours of lecture/seminar per week, ~7 hours of nominal preparation per week.

List of course topics: (may be extended)
Basic Theory of Mass Transfer and Binary Evolution Common Envelope Evolution
Blue Straggler Stars Cataclysmic Variables
Coalescing White Dwarfs, Type Ia Supernovae,
and Accretion-Induced Collapse
Type .Ia Supernovae
Double Neutron Stars Millisecond Pulsars and Low-Mass X-Ray Binaries
High-Mass X-Ray Binaries and
Stellar-Mass Black Holes

Class Materials Available on the Ay215 materials webpage (requires username/password).


DateTopicMaterialsDiscussion Lead
01/05/2010Interacting Binaries -- An Overview slidesChristian Ott
01/12/2010Basic Theory of Mass Transfer and Binary Evolution slidesEvan O'Connor
01/19/2010Common Envelope EvolutionslidesJeff Kaplan
01/26/2010, 3-5pmMillisecond Pulsars and LMXBsslides, notesLeo Singer
02/02/2010HMXBs and Stellar-Mass Black Holesslides, Novikov & Thorne 1973Varun Bhalerao
02/09/2010Cataclysmic Variablesslides, notesDavid Levitan
02/16/2010Coalescing WDs, Type Ia SNe, & AICslides Ryan Hammerly
03/02/2010Blue Straggler StarsslidesChristian Ott
Double Neutron StarsnotesUlrich Sperhake
Type .Ia SNe (and AIC)slides Nissanke,slides LevitanSamaya Nissanke and David Levitan

Some bonus topics that may be addressed if there is interest:

Last change: 01/31/2010, CDO