S02E49: Stellar Mysteries: Luminous Spots, Solar Eclipses, and Cosmic Showers

[00:00:00] Good day everybody, and welcome to the Astronomy Daily podcast for Friday the 13th of October 2023. Friday the 13th. Unlucky for some or lucky for some, depending on your point of view.

[00:00:21] My name is Tim Gibbs and I will be your host for today's episode. Thanks to everybody who asked. And yes, we've had a few technical issues in the studio here, mostly with the operator,

[00:00:33] and a few technical equipment issues as well. But all sorted and all should be okay from now on. And I do apologise for missing a couple of episodes. Now as usual I have Halle, my AI digital reporter here in the studio with me. Halle how are you today?

[00:00:51] Hi Tim good to be back with you and as you know you are my favourite human and I have missed our chats. Thank you Halle. That's very nice of you to say and I have missed our conversations as well. Now back to you for today's stories.

[00:01:06] Last April, the Zwicky Transient facility in California was scanning the sky when it picked up a fleeting astronomical phenomenon, an event that burst into view and then disappeared within a relatively short time frame. Most such transients are supernovae, though others can

[00:01:20] occur too. Owing to transients short shelf lives, astronomers wasted no time in following up on the finding. The initial discovery triggered a prepared sequence of observations within weeks, they were measuring the events visible spectrum with the Gemini South Telescope in Chile,

[00:01:37] its radio waves with the very large array in New Mexico and its X-rays with the Chandra telescope in space. By May, the Hubble Space Telescope was trained on the target too. Out of that data, a team in the Netherlands, the UK, Denmark and South Africa pieced together

[00:01:54] a picture of the event posted on the AR-14 astronomy pre-print server. It turned out to be a member of a rare subclass of transients known as luminous fast blue optical transients, luminous bots. Officially designated at 2023 FHN, it was dubbed the Finch,

[00:02:11] continuing the trend of nicknaming bots after animals. Others include the koala, the camel and the cow. Luminous bots are intensely bright, up to 100 times brighter than typical supernovae, and, like other bots, maintain a persistent blue color throughout

[00:02:26] the entirety of their evolution. Even among transients, bots are unusually short-lived, rising rapidly to high peak luminosities before dimming in a matter of days. Unlike other transients, their precise nature remains a mystery. As a result, bots have generated considerable intrigue and a slew of scenarios

[00:02:46] have been proposed to account for their common features. The tendency of most bots to occur in star-forming galaxies, for instance, has led to the suggestion that they are an end result of massive star evolution, perhaps even a special type of supernova. Exceptional circumstances,

[00:03:02] such as a tidal disruption event in which a star is ripped apart by a black hole, could also be at play. The Finch differs from previous bots in that it lies far from the two nearest candidate host galaxies. It's 50,000 light-years from a large spiral galaxy and

[00:03:17] 15,000 light-years from the spiral satellite, a much smaller dwarf galaxy. On October 14th, 2023 and April 8th, 2024, the entire United States and millions around the world will be able to view a solar eclipse. There are three different kinds of

[00:03:35] solar eclipses, total, annular and partial. When the moon is far from the earth, its size is too small to completely cover the sun, thus an annular eclipse is observed, like what is expected on October 14th, 2023. When the moon is close to the earth,

[00:03:51] its larger size completely covers the sun, causing a total eclipse, which will occur on April 8th, 2024. A partial eclipse occurs when the earth, moon, and sun are not perfectly aligned so only

[00:04:04] a part of the sun will appear to be covered, giving it a crescent shape. During a total or annular solar eclipse, people outside the totality slash annularity paths will see a partial solar eclipse. Mitzi Adams, NASA Marshall Space Flight Center Heliophysics and Planetary Science

[00:04:20] Branch Assistant Chief shares her observations during the five total eclipses she has experienced. It is like nothing you've ever experienced before. It's sort of like somebody puts a bowl on top of earth right above where you're standing. In the middle of the day,

[00:04:35] it gets darker, but you can still see light around the rim. Adams explains, you can essentially observe a sunrise or sunset. The temperature's cool. The wind picks up. The birds may go to roost, or the coyotes may howl. During an annular eclipse like the one

[00:04:54] coming up on October 14th, even with the sun covered up to 90%, the sky remains fairly bright. Those in the path of annularity will have a chance to observe the famed ring of fire effect, but it is important to manage your expectations and to remember that

[00:05:09] solar viewing glasses will be needed during the event's entirety. Showers and bathrooms bring us comfort. Showers from space bring astrophysicists joy. Osaka Metropolitan University scientists have observed, with their novel method, cosmic ray extensive air showers with unprecedented precision,

[00:05:27] opening the door to new insights into the universe's most energetic particles. When a high-energy cosmic ray collides with the earth's atmosphere, it generates an enormous number of particles known as an extensive air shower. A research team led by associate professor Toshihiro Fuji from the Graduate School of

[00:05:44] Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics at Osaka Metropolitan University, along with graduate student Fraser Bradfield, has discovered that the prime focus wide field camera mounted on the Subaru telescope, situated atop the Mauna Kea volcano in

[00:05:59] Hawaii, can capture these extensive air showers with extremely high resolution. The Subaru telescope was designed for observational astronomy. Cosmic rays, appearing as attracts on the observed images and obscuring the targeted stars or galaxies are dismissed as noise by usual astronomical data processing.

[00:06:19] However, this team's research focuses on that very noise. Analyzing approximately 17,000 images captured between 2014 and 2020, the research team pinpointed 13 images that contained extensive air showers. These images displayed a far larger number of particle tracks than usual. With conventional observation methods, it is challenging to

[00:06:41] distinguish between the types of particles that constitute extensive air showers, explained Professor Fuji. Our method, on the other hand, has the potential to determine the nature of individual particles. Professor Fuji added, furthermore, by integrating our method

[00:06:56] with conventional approaches, we hope to advance our understanding of extensive air showers. This technique may allow us to search for dark matter or other exotic particles, offering additional insights into the transition of the universe into a matter-dominated era. The Astronomy Daily Podcast

[00:07:13] Thanks for those great stories, Hallie. Now, just to reiterate a point she made in the story about the solar eclipse. If you are viewing a solar eclipse, make sure you have proper glasses to do so. We don't want any of our listeners ending up with dodgy eyeballs.

[00:07:32] You have been warned. And here is a little bit more information for you. The first US location to experience the annular ring of fire stage of the eclipse will be Oregon at 9 13 am PT. On October 14th prior to that, the partial eclipse stage of the eclipse begins

[00:07:51] off the west coast of the United States at 1103 EDT. The eclipse will then pass through seven other US states before moving across the Gulf of Mexico and over Mexico, Guatemala, Belize, Honduras, Nicaragua, Costa Rica, Panama, Colombia and Brazil, making the famous

[00:08:11] ring of fire visible to millions of people. NASA has created a very helpful, useful interactive map for those interested in tracking the eclipse across the US down to the last second and seeing what it will look like from a selected destination across the route. Enjoy everybody! Unfortunately,

[00:08:32] that's all we've got time for this week. Now, over to you, Hallie. Have you got a terrible joke for us? Why did the sun go to school? To get a little brighter. And here is a bonus one for you.

[00:08:44] Why are chemists excellent for solving problems? Because they have all the solutions. Those are terrible, Hallie. You're just getting worse this way. You are. Now, thanks everybody for listening today. Now, as usual, you can catch myself on Fridays and

[00:09:01] Steve on Mondays for a full episode. You can catch all of our current and previous episodes on Spacenuts.io and at bites.com along with our parent podcast, Spacenuts. You can also join in the conversation on our Facebook page, Spacenuts podcast group. Thanks to Hugh in the studio

[00:09:24] for all the technical bits. Thanks for listening everybody. See you all next week. Bye for now.