Asteroseismology is this subfield of stellar astrophysics concerned with the interpretation of the information contained in the normal modes of vibration detected in pulsating stars. These normal modes correspond to waves of the gravito-acoustic type that may be seen as real "probes" of the global and internal structure of a star. In particular, the comparison of the periods of the observed modes in a pulsating star with periods computed from stellar models allows, in principle, the determination of the global parameters of the star (e.g., mass, radius, effective temperature, luminosity) as well as its internal structure (e.g., profile of the chemical composition, location and extent of possible convection zones, depth of regions of nuclear burning). Rotation of a pulsating star also leaves a specific signature on the periods of oscillation. This signature has been well known for quite some time, but, with the exception of the Sun, has remained unexploited until quite recently. In this talk, I will first present a summary of the basic principles of the theory of stellar pulsations, including a brief description of the effects of rotation on the pulsation periods. With the help of an original approach developed in Montréal and Toulouse to exploit the signature of rotation in pulsating stars, I will then summarize the results of a recent exercise that has led to the first detailed mapping of the internal rotation profile of a star other than the Sun. It appears from this, and similar studies that we carried out since, that isolated white dwarf stars rotate extremely slowly *and* rigidly, thus demonstrating that such stars have essentially lost all of their angular momentum in previous evolutionary phases.
Refreshments will be available before the colloquium, at 3:45 pm, in the lobby of Dane Smith Hall.
Individuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact Daniel Sandoval (phone: 505-277-2616, email: daswerto@unm.edu) well in advance to ensure your needs are accommodated. Event handouts can be provided in alternative accessible formats upon request. Please contact Mr. Sandoval if you need written information in an alternative format.
University of New Mexico Department of Physics and Astronomy -
MSC07 4220 -
800 Yale Blvd NE
Albuquerque, New Mexico 87131-0001
Phone: (505) 277-2616
Fax: (505) 277-1520
Comments/questions about this web page? Email webmaster@phys.unm.edu
Spring 2009
Individuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact Daniel Sandoval (phone: 505-277-2616, email: 
People
Faculty