Astronomy Colloquium / Fall 2006

October 4th

Dr. Sarbani Basu

Yale University

Journey to the Centre of the Sun

Helioseismology has allowed us to study the Sun in unprecedented detail. Using this tool we had been able to determine the structure of the Sun well enough to know that the solar neutrino problem did not arise because of deficiencies in solar models long before the neutrino experiments found that some of the solar neutrinos change flavour. The current thrust of helioseismology is in studying how the Sun changes over short time-scales that are related to the solar activity cycle. We now know, for example, that solar rotation rate changes with time and that the changes mimic the butterfly diagram, pointing to a link between solar dynamics and solar activity.

In this talk I shall give a brief introduction to helioseismology. I shall then go on to describe some of the important results that we have obtained. I shall also touch upon the recent controversy over solar abundances and what helioseismology can say about that.