Ask an Astronomer - Music of the Stars

Topic: Ask an Astronomer - Music of the Stars
Time: Sep 11, 2021 05:00 PM India
Speaker: Prof. Anwesh Mazumdar
Title: Music of the stars

Abstract: "Twinkle, twinkle, little star, How I wonder what you are..." --- Astronomers, much like children, have always pondered on the questions of what stars are, how they are born, how they are built on the inside, and how they change over their lives. While we can see stars by their light, all the visual information comes from the outermost layers of stars. Stars are extremely opaque objects, and we cannot really look inside stars. How are we then to know the internal structure of stars? Asteroseismology, or the study of stellar oscillations, is the science that helps us to do this. Stars continually vibrate with multiple characteristic frequencies, and every frequency of vibration is associated with a wave that penetrates the star up to a certain depth. These vibrations, although usually extremely tiny in amplitude, can be detected through continuous precise measurements of the starlight. The frequencies of these vibrations encode information about the internal structure and composition of the star, much like the frequencies of vibration of a string in a musical instrument depends on the material and dimensions of the string. By analysing these oscillations in a number of stars, we have been able to test and refine our theoretical knowledge of stellar structure and evolution. This talk will bring out the basic ideas behind asteroseismology and highlight some of the exciting results obtained so far.