The 365 Days of Astronomy

365DaysOfAstronomy.org
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Sep 9, 2025 • 34min

Ask A Spaceman Ep. 255: How Do The Biggest Stars Get So Big?

How do we measure the sizes of stars? What are the biggest ones today, and how big could stars have gotten in the past? Is there any way for a star to cheat and get even bigger? I discuss these questions and more in today’s Ask a Spaceman!   Support the show: http://www.patreon.com/pmsutter All episodes: http://www.AskASpaceman.com Watch on YouTube: http://www.youtube.com/PaulMSutter Read a book: https://www.pmsutter.com/books   Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE!   Big thanks to my top Patreon supporters this month: Justin G, Chris L, Alberto M, Duncan M, Corey D, Michael P, Naila, Sam R, Joshua, Scott M, Rob H, Scott M, Louis M, John W, Alexis, Gilbert M, Rob W, Jessica M, Jules R, Jim L, David S, Scott R, Heather, Mike S, Pete H, Steve S, Lisa R, Kevin B, Michael B, Aileen G, Steven W, Deb A, Michael J, Phillip L, Mark R, Alan B, Craig B, Mark F, Richard K, Stace J, Stephen J, Joe R, David P, Justin, Robert B, Sean M, Tracy F, Ella F, Thomas K, James C, Syamkumar M, Homer V, Mark D, Bruce A, Tim Z, Linda C, The Tired Jedi, Gary K, dhr18, Lode D, Bob C, Red B, Stephen A, James R, Robert O, Lynn D, Allen E, Michael S, Reinaldo A, Sheryl, David W, Chris, Michael S, Erlend A, James D, Larry D, Karl W, Den K, Tom B, Edward K, Catherine B, John M, Craig M, Scott K, Vivek D, Barbara C, Brad, and Azra K!   Hosted by Dr. Paul M. Sutter.   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 8, 2025 • 29min

Astronomy Cast Ep. 155: Dwarf Stars

http://www.astronomycast.com/archive/ From September 14, 2009. We think we live near an average star, but that’s not the case at all. Compared to most stars in the Universe, the Sun is a giant! Let’s look at the small end of the stellar spectrum, to stars with a fraction of the size and mass of our own Sun. There are many ways that a star can get small, and they lead dramatically different lives and deaths.   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 7, 2025 • 6min

Travelers in the Night Eps. 329 & 330: Near Neighbor & Comet Johnson

Join Dr. Al Grauer as he uncovers thrilling astronomical discoveries! A new space rock, 2017 AG13, zooms past Earth every 345 days and recently passed within 9 lunar distances. Don’t worry, it won't return until 2091. Then, learn about Comet Johnson, traveling from deep space with a chance to be seen by the naked eye. Though it stays 75 million miles away, its outgassing might make for a spectacular sight. Discover the dynamic dance of celestial bodies and the vital role of asteroid detection!
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Sep 6, 2025 • 1h 37min

Awesome Astronomy - September Part 1: Paul in Festival Land

Paul Hill, Ralph Wilkins and Dr. Jenifer “Dr. Dust” Millard host.  Damien Phillips, John Wildridge and Dustin Ruoff produce. [Editor’s note: This episode is 1 hour 37 minutes long.] A bumper end of summer episode with Paul out in the world of science outreach and communication in a Summer music festival. There’s also discussion of the new Astronomer Royal, China’s moon program, Starship and a deep dive on the Mars Reconnaissance Orbiter.   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 5, 2025 • 20min

EVSN - Europa May Have Enough Heat for Seafloor Volcanoes

From May 27, 2021. Jupiter’s moon Europa, an icy world with a subsurface ocean that interests astrobiologists, may actually be hot enough to melt the interior rock and create volcanoes on the ocean floor. Plus, Ryugu, giant planets, fossil discoveries, Martian glaciers, and this week’s What’s Up!   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 4, 2025 • 31min

Actual Astronomy - Observer’s Calendar For September

September brings exciting celestial events! Witness the Aurigids meteor shower linked to Comet Keiss, first observed in 1911. Look for Venus shining near the Beehive Cluster and don’t miss a lunar eclipse. The hosts share tips for spotting these phenomena, including the occultation of Venus by the Moon. They also discuss the newly discovered Comet C2025A6 Lemon and its potential brightness, stirring enthusiasm for observational challenges. Community engagement is celebrated, inviting everyone to join in the wonders of the night sky.
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Sep 3, 2025 • 14min

Cheap Astronomy - Dear Cheap Astro Ep. 123: The Big Questions

Asking questions and not always answering them. Is there hope? Well, sure. The question arises where the Drake Equation, aiming to quantify the likely number of detectable intelligent civilizations out there includes a term representing the inherent risk of any intelligent civilization destroying itself. It is just a risk, could be low could be high, but its wide acceptance as a part of the whole equation does suggest we have some pessimism about our own future.   Could dark matter be black holes? Well, no. Firstly. we've discussed before how black holes can't really be dark matter. Dark matter is not only invisible, but it's also transparent. Black holes can be invisible against a black background and after all space is a black background.   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 2, 2025 • 6min

Exoplanet Radio Ep. 41: Exoplanet Secondary Eclipses: Catching a Planet in the Shadows

https://www.youtube.com/watch?v=RucWv35XwD0 Hosted by Tony Darnell. From  Oct 11, 2023. Over the course of this show, we’ve talked many, many times about the Transit Method for detecting exoplanets.  It is simply the measure of a star's decrease in brightness as the star passes through our line of sight.  This once difficult measurement has now become commonplace and can even be done with advanced amateur astronomy equipment under a reasonably dark sky.   From this measurement, we can infer a few things about the planets passing by: we can get an indication of its size and if we measure several transits, we can get the period of the orbit around the host star.  We can also get an estimate of the period and eccentricity of the orbit by the width of the dip in the light curve.   But there is another, even more difficult measurement we can make using transit telescopes that are an important tool for learning about planets around other stars: exoplanet secondary eclipses.   Get all episodes: https://exoplanetradio.com Music by Geodesium: https://lochnessproductions.com   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Sep 1, 2025 • 46min

Astronomy Cast Ep. 126: From Skeptics Guide With Questions

http://www.astronomycast.com/archive/ From February 9, 2009. This week Bob Novella of the Skeptics Guide to the Universe podcast is going to pepper Pamela with questions, testing her ability to leap from tides to gravitational waves to Higgs bosons. We’ll see where this takes us on this skeptical journey through what is known and what we’re trying to learn about this Universe. [Editor’s note: A small bit of audio at the start of two of Bob’s questions was lost due to a technical glitch. So I inserted a coo-coo clock sound effect. Things were going coo-coo after all…]   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
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Aug 31, 2025 • 6min

Travelers in the Night Eps. 327 & 328: Suddenly Bright & The Heat is On

Discover the astonishing story of 2017 AG5, a massive space rock that unexpectedly brightened the skies and was tracked worldwide. At 370 feet, it poses a close approach risk to Earth, reminiscent of a cosmic surprise. The conversation also dives into alarming climate data, revealing 2016 as the hottest year on record, with temperatures 1.8°F above average and a staggering 7.2°F increase in the Arctic. A vivid reminder of how human activity is accelerating climate change, making both topics essential for our future.

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