The best podcast for people interested in astronomy

    When I was dabbling in my interest astronomy, one of the places I went to find more information was podcasts. Personally, I have a hard time reading a lot of scientific papers as they tend to be kind of dry and, unless I have a paper as an assignment, I like to find a source of information that is both entertaining and accurate and backed up with research. Now, like everything, there are some good podcasts that are very informative and are enjoyable to listen to, however there are others that are really fun to listen to yet have no information based on research and fact, and others that are uninformative and portrayed poorly. My hope is that this blog gives you resources to a number of podcasts and honest opinions on the ones that are worth your time and the ones that are not.

    This first podcast I want to discuss is Astronomy Cast hosted by Fraser Cain and Dr. Pamela Gay. Fraser Cain is the producer of Universe Today, which is a platform for space and astronomy information. He partnered with Pamela Gay who is an astronomer and writer. Professionally, Pamela Gay is a senior Scientist at the Planetary Science Institute where she is the chief herder for CosmoQuest. Granted, you can only take what you find on the internet by face value but with that being said, this podcast is well researched and supported. 

    My favorite episode of theirs was episode 560 titled Betelgeuse. This episode was made back on February 24th, 2020 after the dimming of the red giant Betelgeuse. In this episode they talk about the reasons that the star could be dimming and what would happen if it were to go supernova. To introduce their audience to the star Betelgeuse they explain how when the star was still young and on the main sequence it would have been just under 20 solar masses (to give you a comparison our sun is 1 solar mass). Betelgeuse was also once an O-type star on the main sequence meaning it was on the top left side of a Hertzsprung Russell diagram. Now the star is no longer burning hydrogen in its core so it has moved of the main sequence of stars and on the HR diagram (seen above) it has moved up and to the right of where it use to be. The interesting thing about Betelgeuse that they explain in this episode is how the dimming of the star may be a sign of the star’s death. They explain this star is what they call a runaway star, which means it is traveling at a significant velocity through space. As a result of this and that a star this large  has so many layers of fusion happening layers have been coming off because there is not enough gravity or another way to put it is the attractive force between the center of the star where is has so much more mass packed together has the weakest hold on the exterior layer of the star which means those layers are more likely to be blown off while the star is moving at such high velocity. 

Like all stars, there comes a point where they can no longer continue fusing elements in their core because it takes too much energy to create fusion of certain compounds. Because of this, the core of the star will begin to collapse on itself and, it will no longer produce energy in the form of light. Fraser Cain and Pamela Gay talk about this happening in Betelgeuse and how the halt of the star being able to use fusion to create its energy will cause the star to gradually collapse on its self because the light pressure (referred to as the radiation pressure in more formal setting) is no longer being produced and pushing from the inside of the star out. The only force acting on the star will be its own gravitational pull as the core of the star condenses and gets smaller and smaller which means the rest of the star’s layers will begin collapsing inward as well. But what makes this so interesting and what they discuss in the episode is what happens after this collapse takes place and what that means for us.

Betelgeuse is approximately 20 solar masses, which is huge. Using some everyday logic, we know the larger the star the bigger the death of that star, and in Betelgeuse’s case it will probably be much smaller in its final life due to how much of its mass was lost throughout its lifetime. However, it will still be a giant compared to our own sun. When Fraser Cain and Pamela Gay are discussing what they believe might happen to Betelgeuse when it decays they believe that as the star collapses in on itself the collapsing will accelerate because as all of that mass is pulled in closer it attracts the mass farther out more but as it does this, it creates pressure which as the collapse will still be accelerating and increasing until a supernova occurs. Now in the episode they make a comparison saying that this supernova would leave behind a nebula and neutron star. Gay and Cain compare it to the crab nebula but note that Betelgeuse’s nebula will be ten times closer to us than the crab nebula. This could mean we would be able to see this nebula with an unaided eye as it would be a prominent blob in the sky. I do not know about everyone else, but I think being able to see a nebula like that would be pretty incredible. 

As Pamela Gay and Fraser Cain wrap up the episode, they speculate the effects this might have on the future of storytelling with the sky and other not as critical topics which is half the charm of the episode and podcast platform as a whole. They find this blend of informative and entertaining while still making you think for yourself and think about the “what Ifs…” and “well maybe’s”. I hope this gave you a taste of this podcast platform and the type of information they are presenting to their audience.

Sources:

Cain, Fraser, and Pamela Gay. “Ep. 560: Betelgeuse.” Astronomy Cast, 29 Feb. 2020, www.astronomycast.com/2020/02/ep-560-betelgeuse/.

Jacksonville, Florida State College at. “Astronomy Lab.” Lumen, courses.lumenlearning.com/atd-fscj-astronomylab/chapter/h-r-diagram-for-milky-way-stars