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A Celestial Feast: Thanksgiving Under the Stars · Star Trails: From Backyard Astronomy to Cosmic Wonder

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Howdy Stargazers, and welcome to this episode of Star Trails.
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I'm Drew, and I'll be your guide to the night sky for the week starting November 24th to
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the 30th.
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It's Thanksgiving week here in the U.S., a time for gathering with loved ones, reflecting
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on what we're grateful for, and maybe even sharing a moment under the stars.
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In this episode, we'll look at some lesser-known constellations you can see this time of year,
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and later in the show, we'll explore the cosmic bubble our solar system resides in,
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and how our place in the universe might be connected to others like it by a series of
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tunnels.
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The cosmos have a feast in store for us this week, so grab a comfortable spot under the
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night sky, and let's enjoy some celestial side dishes for the holiday.
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First up, the moon.
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Early in the week, we're in the last quarter phase, with the moon slowly slimming down
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to a waning crescent by Thanksgiving and beyond.
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That means less moonlight washing out the stars, giving us darker skies, perfect for
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spotting some of the treasures we'll talk about tonight.
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Venus and Jupiter are stealing the show this week.
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You can catch Venus just after sunset in the western sky, shining at a bright negative
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four magnitude, making it the brightest object in the night sky after the moon.
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Jupiter is sitting bright and bold in the constellation Taurus.
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It begins its rise around 6 p.m. and reaches its highest point in the sky by 1 a.m.
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If you have a telescope, you can glimpse its cloud belts or the dance of its four largest
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moons, E.O., Europa, Ganymede, and Callisto.
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Saturn, over in Aquarius, is another highlight.
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Even a small telescope will reveal its iconic rings, a sight that never fails to amaze.
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Catch it before it sets around midnight.
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For early risers, Mars makes a brilliant appearance in cancer during the pre-dawn hours.
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Look for it near the Beehive cluster M44 for a stunning view.
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Lastly, don't forget Uranus.
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It's still near its opposition in Taurus, making it a prime time to spot this distant, icy
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world.
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Look for it just off to the right of the Pleiades.
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And while we're near the Pleiades, let's talk about how it's been celebrated in myths
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across cultures, often associated with family and the harvest.
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The ancient Greeks saw them as the Seven Sisters, while Native American tribes like the Lakota
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and Cherokee linked them to stories of kinship and survival.
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The Pleiades were also a seasonal marker guiding farmers to know when to plant and harvest,
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a perfect connection to Thanksgiving's roots as a harvest festival.
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Resembling a tiny dipper, the cluster is visible to the naked eye, but binoculars will reveal
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even more stars, each sparkling like diamonds on black velvet.
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Speaking of harvests, think about Jupiter and Saturn.
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These two planets represent abundance and stability in mythology.
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Jupiter as the bringer of bounty and Saturn as the god of the harvest.
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Seeing them bright in the night sky feels like a cosmic reminder to appreciate the gifts
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we have and share them with others.
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And while the big meteor showers are behind us, a few Leonid meteors may still streak
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across the sky, especially earlier in the week.
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As we approach the skies of winter, let's take a moment to examine a few of the lesser
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known constellations that adorn the sky this time of year.
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We'll start with Eradinas, one of the longest constellations in the night sky.
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Known as the Celestial River, Eradinas stretches across the southern sky, beginning the Erygel
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and Orion, and winding its way toward the far reaches of the southern hemisphere.
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In Greek mythology, Eradinas represents a river, often associated with the River Poe
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in Italy or the mythical river of the underworld.
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The constellation's most famous star, Akronar, marks its end point.
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Akronar is the ninth brightest star in the sky, but here's the catch.
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You can only see it from the southern hemisphere, or very low latitudes in the northern hemisphere.
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For those of us further north, the visible portion of Eradinas is still impressive, with
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stars tracing a serpentine path through the sky.
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This constellation is also home to the Eradinas Supervoid, a vast region of space with very
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few galaxies, baffling astronomers to this day.
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If you have a telescope, you might also spot NGC 1232, the Eye of God Galaxy, a stunning
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spiral galaxy that lies roughly 60 million light years away.
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Next, let's explore Auriga, the charioteer.
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High in the northern sky, this constellation is easy to find thanks to its brightest star,
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Capella, a golden giant that ranks as the sixth brightest star in the night sky.
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Capella is part of a binary star system and represents the charioteer's goat.
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Auriga is a treasure trove for stargazers.
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It contains three stunning open star clusters, M36, M37, and M38.
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These clusters are perfect examples of young stars born in the same stellar nursery still
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bound together by gravity.
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In mythology, Auriga is often depicted as a charioteer holding a goat and her kids,
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a nod to its association with agriculture and herding.
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For the modern observer, Auriga symbolizes cosmic abundance with its stars and clusters
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offering something for everyone, whether you're peering through binoculars or simply gazing
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up with the naked eye.
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Finally, we come to Monoceros, the unicorn, a constellation that feels like it belongs
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in a storybook.
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Unlike the bright constellations we've covered so far, Monoceros is faint and requires dark
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skies to fully appreciate.
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It's nestled near Orion, Canis Major and Canis Minor, acting as a bridge between these more
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prominent constellations.
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But don't let its faintness fool you.
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Monoceros is brimming with treasures.
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This constellation is home to the Rosette Nebula, a massive cloud of gas and dust shaped
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like a blooming flower.
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Just by, you'll find the Christmas tree cluster, a charming group of stars shaped as its name
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suggests like a holiday tree.
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These objects are accessible with binoculars or a small telescope and are especially beautiful
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for astrophotographers.
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Monoceros was introduced in the 17th century, making it a relatively modern addition to
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the night sky.
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Tonight, we're taking a closer look at our solar system's cozy spot in the galaxy.
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Imagine this, we're not just floating in empty space, we're actually sitting inside
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a giant bubble, not like a soap bubble but something called the local hot bubble.
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It's invisible to the naked eye but it's a cosmic wonder that tells an incredible story
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about the violent history of our galactic neighborhood.
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And there's some brand new science about this bubble that's blowing astronomers minds,
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including the discovery of mysterious tunnels that may connect our bubble to others.
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Around 10 to 20 million years ago, a massive star in our corner of the Milky Way reached
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the end of its life, exploding in a brilliant supernova.
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The force of that explosion sent shock waves rippling outward, carving a massive cavity
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in the surrounding interstellar gas and dust.
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But that wasn't the end of it.
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Astronomers think that multiple supernova went off in this same region, one after the
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other, creating an enormous, interconnected region of hot, sparse gas.
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That region is known as the local hot bubble.
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It's about 1000 light years across and while the gas inside is searingly hot, millions
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of degrees, it's also incredibly thin, like a faint wisp of a breeze.
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Although our solar system is almost right in the middle of this bubble, the gas is so
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diffuse that it doesn't affect us here on Earth.
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So if we can't see this bubble, how do we even know it's there?
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The key is X-rays.
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The superheated gas emits faint X-rays and astronomers using modern space telescopes
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can detect them.
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By mapping these X-rays along with the distribution of interstellar dust, scientists have pieced
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together the shape and size of the local hot bubble.
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Using data from E. Rosita, an instrument built by the Max Planck Institute for Extraterrestrial
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Physics to map cosmos, researchers recently created a detailed 3D map of this bubble.
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The map revealed some unexpected features, including an interstellar tunnel extending
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toward the constellation Centaurus.
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This tunnel may connect the local hot bubble to a neighboring super bubble, such as the
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gum nebula, creating kind of a galactic highway for hot gas to flow.
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The local hot bubble isn't unique, space is full of these bubbles formed by similar
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supernova explosions.
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For instance, the Loop 1 bubble near the Scorpius-Centaurus region overlaps with our bubble.
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The Orion-Iradanus bubble, connected to the famous Orion nebula, also lies nearby.
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These bubbles don't exist in isolation, they're part of a larger network connected by tunnels
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carved through the cooler interstellar medium.
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Think of it as a cosmic web where hot gas flows freely between these structures.
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So why is all this important?
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The local hot bubble isn't just a historical artifact, it actively shapes our solar system's
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environment.
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The hot gas acts as kind of a buffer, influencing how cosmic rays and other interstellar particles
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reach us.
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It also tells us something about the dynamics of the Milky Way.
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For example, these bubbles influence star formation.
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The edges where hot gas meets cooler material can compress gas enough to form new stars.
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The tunnels, like the one towards Centaurus, give us clues about how energy and matter
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flow through the galaxy.
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These recent findings are part of a growing understanding of the galaxy's structure.
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The Eroseta data has even revealed temperature differences within the bubble itself, with
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the southern hemisphere being slightly hotter than the northern.
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This uneven heat distribution reflects the chaotic nature of the multiple supernova explosions
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that shape the bubble.
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Before we wrap up, here are some other fun facts about our local bubble.
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If the local hot bubble were visible, it would look like a faintly glowing sphere surrounding
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us in the night sky.
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Our solar system entered the local interstellar cloud about 100,000 years ago, and we might
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leave it in another 20,000 years or so.
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When this happens, we could encounter a different region of the bubble or maybe even pass into
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one of those interstellar tunnels.
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Also, the edges of these bubbles, like the Orion Nebula, are some of the most visually
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stunning and dynamic places in the galaxy.
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The local hot bubble and its surprising connections to the rest of the galaxy is yet another reminder
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that even in the vast emptiness of space, there's always something happening.
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Next time you gaze up at the stars, think about the bubble of hot gas cradling our solar system
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and the supernova that helped shape our tiny corner of the galaxy.
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Thanks for joining me this week on Star Trails.
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I'm grateful for all of you, my fellow stargazers, and the chance to share the wonders of the
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cosmos.
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If you found this episode useful, please share it with a friend.
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The easiest way to do that is by visiting our website, startrails.show, where you can
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find all of our episodes, including transcripts, night sky maps, and more.
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Until next time, keep looking up and exploring the night sky.
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Clear skies, everyone.