Supernovae: The Brilliant Endings of Massive Stars - Michael Pajkos - 01/12/2024

When stars heavier than our Sun reach the ends of their lives, they undergo massive explosions known as supernovae. But why do they explode and why do some of them result in neutron stars or black holes? Join us for a 30-minute lecture investigating supernovae, followed by a panel Q&A consisting of several astrophysicists to answer your questions about astrophysics and space science. Timestamps below:

00:00 Announcements
04:51 Intro to Supernovae Presentation
06:00 Supernovae Presentation
41:20 Q&A for Supernovae Presentation
41:51 "Why do some stars have a sharp transition in their interiors?"
43:59 "How do we interpret the gravitational wave signal from the supernova?"
46:25 "Why do constellations never change?"
48:55 Intermission
52:20 Q&A Panel Introductions
55:32 "Are black hole remnants from supernova similar in size to neutron star remnants?"
57:29 "Could we ever feel gravitational waves?"
1:01:04 "How long does a supernova last?"
1:06:46 "How do we identify the location of a gravitational wave source?"
1:09:39 "What's hotter: a star's core or a neutron star's core?"
1:12:47 "How much does chaos play a role in a supernova's collapse?"
1:18:05 "Can the r-process create new elements instead of just new isotopes?"
1:19:53 "What percent of your research is observation-based vs theory-based?
1:21:43 "Are we seeing more supernova now than we did 100 years ago?"
1:26:00 "Explain dark matter, dark energy, quarks, gluons, and supernova locations?"
1:36:40 "What forces contribute to stellar collapse?"
1:39:23 "How fast do gravitational waves travel; how long are they present?"
1:42:52 "Are certain types of neutrinos more observable than others?"
1:45:26 "Do the gradation waves in supernovae travel faster than light?"
1:46:17 "Can we detect supernovae before they explode?"
1:49:29 "Why were the neutrinos detected from SN1987A exciting?"
1:50:38 "What does it mean for the universe to be flat?"
1:53:20 "How does a supernova become a black hole?"
1:54:25 "Has JWST revealed more mature galaxies at the edge of the universe than expected?"
1:58:56 "Does our Sun have a density gradient similar to the supernovae discussed?"
1:59:45 Concluding Remarks

Title: Supernovae: The Brilliant Endings of Massive Stars
Speaker: Michael Pajkos
Abstract:
When stars heavier than our Sun reach the ends of their lives, rapid changes inside the star can result in it exploding as a supernova. While these supernovae may produce brilliant outbursts that are visible across the universe, many will often fail, producing instead a stellar implosion. In this talk, we will review the science that governs whether a star will turn into a cosmic firework or stellar dud. We will explore the hearts of these cosmic furnaces that produce unique objects like neutron stars and black holes. Lastly, we will discover what items on a grocery list, stellar explosions, and humanity all have in common.

Photo Credit: M. Weiss / Harvard CfA