Astronomy and Astrophysics - An Introductory Survey, A lecture series by Prof. G. Srinivasan - Lecture 19 - PULSARS

In 1967, a young Ph.D. student Jocelyn Bell discovered an object that `twinkled' in the radio wavelength. This `twinkling', appearing like a regular train of radio pulses, would later be identified with the beamed radiation from a neutron star. A decade later, an artist used a `stacked plot' image of a large number of successive such radio pulses as a record label and it ended up being an iconic image in popular culture. Originally though, the image was created by Harold Craft for his Ph.D. thesis at the Arecibo Observatory, using data from the very pulsar Jocelyn Bell discovered. ABOUT THE LECTURE Twinkle twinkle little star. In August 1967, Jocelyn Bell, a young student at Cambridge University discovered something that twinkled at radio wavelength. It turned out to be a really ‘little star’! It soon emerged that she had made one of the greatest discoveries in astronomy; she had discovered a neutron star. Since then, nearly three thousand neutron stars have been discovered. In this lecture, I shall explain how a neutron star produces electromagnetic radiation and why it ‘pulses’. ABOUT THE LECTURE SERIES This lecture series is organized by the Astronomical Society of India as a part of its Golden Jubilee celebrations. Aimed at undergraduate and graduate students, this series of talks by renowned astrophysicist and teacher, Prof G. Srinivasan, starts from the first principles of Physics and builds up the subject rigorously to the present state of our understanding. Series website: https://astron-soc.in/srini-ana The website hosts a question bank as well as a list of suggested reading for each lecture (prepared by Dr. Sushan Konar) ABOUT THE SPEAKER Professor G. Srinivasan In a research career spanning more than five decades, his interests have spanned many aspects of physics and astrophysics. He is a passionate teacher and has authored two outstanding Astronomy texts titled ‘What Are The Stars?’ and ‘Can Stars Find Peace?’ He is a Past President of the Astronomical Society of India, and a Past President of the Division on Space and High Energy Astrophysics of the International Astronomical Union. In his distinguished career he has worked at the University of Chicago, USA; the IBM Research Laboratory in Zurich, Switzerland; Chalmers University of Technology, Goteborg, Sweden; the Cavendish Laboratory, University of Cambridge, England and the Raman Research Institute, Bengaluru Follow us on social media at https://twitter.com/asipoec https://www.facebook.com/asi.poec/ This series is also supported by the IAU OAE Centre in India https://twitter.com/astro4edu_India https://www.facebook.com/OAE-Center-India-105698322030674