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