Twis Week in Astronomy: Dark Energy Might Be Changing, Hidden Star Orbiting Betelgeuse and Rocky Planets Forming

<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
<v Speaker 1>with our soothing Bedtime Astronomy podcast. Each episode offers a
<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for
<v Speaker 1>unwinding after a long day. Let's travel through the mysteries
<v Speaker 1>of the universe as you drift off into a peaceful
<v Speaker 1>slumber under the night sky. Chweeze Week in Astronomy. Dark
<v Speaker 1>energy might be changing hidden star orbiting beetlejuice in first
<v Speaker 1>glimpse of rocky planets forming Dark energy might be changing
<v Speaker 1>over time. Around nineteen ninety eight, scientists made a discovery
<v Speaker 1>that completely changed how we understand the universe. They had
<v Speaker 1>been studying the light from about fifty exploding stars called
<v Speaker 1>type Ia supernova. These explosions happen when a certain kind
<v Speaker 1>of dead star called a white dwarf, blows up in
<v Speaker 1>a very specific way. Scientists used them to try to
<v Speaker 1>measure how fast the universe was expanding, but what they
<v Speaker 1>found was shocking. Instead of slowing down or expanding steadily,
<v Speaker 1>the universe was actually speeding up. Something unknown was pushing
<v Speaker 1>it to expand faster and faster. That mysterious force was
<v Speaker 1>later called dark Energy, and the discovery won a Nobel Prize.
<v Speaker 1>Since then, researchers have continued to observe these supernova using
<v Speaker 1>different telescopes and methods. Over two thousand of them have
<v Speaker 1>now been recorded, but because each experiment is slightly different,
<v Speaker 1>it's hard to compare the results directly, like trying to
<v Speaker 1>compare apples to oranges. To fix that, scientists created the
<v Speaker 1>biggest and most unified collection of Type IA supernova data. Ever.
<v Speaker 1>This new set is called Union three, built by an
<v Speaker 1>international group called the Supernova Cosmology Project led by researchers
<v Speaker 1>at Berkeley Lab. Putting all these supernova on the same
<v Speaker 1>measurement scale, scientists can now study dark energy with greater precision.
<v Speaker 1>The latest analysis suggests that dark energy might not be
<v Speaker 1>staying the same over time. It could be changing. That's
<v Speaker 1>a big deal. It's not yet a solid conclusion, but
<v Speaker 1>it does match what other studies are also beginning to suggest.
<v Speaker 1>One of those is the Dark Energy Spectroscopic Instrument DESI,
<v Speaker 1>which studies the way galaxies group together. Another supernova study
<v Speaker 1>from the Dark Energy Survey seems to show the same pattern.
<v Speaker 1>Even those scientists are cautious and not jumping to conclusions.
<v Speaker 1>They're definitely paying attention. Two very different techniques are starting
<v Speaker 1>to show results that don't quite match what our current
<v Speaker 1>main theory, called the LANDA CDM model predicts. This model
<v Speaker 1>assumes that dark energy has always had the same strength
<v Speaker 1>and that it pushes against gravity, which is mainly caused
<v Speaker 1>by something called dark matter. But now some scientists think
<v Speaker 1>a model where dark energy changes over time might better
<v Speaker 1>match what the data shows. If that's true, it could
<v Speaker 1>completely change our understanding of how the universe works and
<v Speaker 1>even how it might end. Dark energy makes up about
<v Speaker 1>seventy percent of the universe, and it's the reason space
<v Speaker 1>is stretching apart. If it starts to weaken, that could
<v Speaker 1>mean the universe might one day stop expanding so quickly,
<v Speaker 1>or even slow down completely. It could even start to
<v Speaker 1>shrink again. That's why researchers are so eager to understand
<v Speaker 1>how dark energy behaves. To do that, they trace the
<v Speaker 1>history of the universe's expansion by looking at supernova. Because
<v Speaker 1>these explosions always have the same brightness, scientists can use
<v Speaker 1>them like standard light bulbs to measure distance, like using
<v Speaker 1>identical candles to tell how far down the hallway something is.
<v Speaker 1>They also measure how much the light from each other
<v Speaker 1>supernova shifts toward red, which tells them how much the
<v Speaker 1>universe has stretched since the explosion. Union three includes two
<v Speaker 1>thousand and eighty seven supernova from twenty four different studies
<v Speaker 1>and lets scientists look back over about seven billion years
<v Speaker 1>of space history. That's a huge upgrade from the older
<v Speaker 1>Union two data set, which had only five hundred and
<v Speaker 1>fifty seven supernova. To put them all on the same scale,
<v Speaker 1>scientists looked closely at each supernova's brightness over time, how
<v Speaker 1>it gets bright, peaks and fades. That lets them figure
<v Speaker 1>out the true brightness of each explosion and adjust for
<v Speaker 1>any differences like recalibrating candles made by different brands. They
<v Speaker 1>also used a more advanced method to analyze the data,
<v Speaker 1>one that can deal better with uncertainties and incomplete information.
<v Speaker 1>This method is called a Beesian hierarchical model, and it
<v Speaker 1>can handle things like small changes in telescope filters over
<v Speaker 1>time that might affect how how much light was recorded.
<v Speaker 1>This makes the final results more accurate than before. In
<v Speaker 1>the near future, scientists plan to add even more data
<v Speaker 1>to Union three, especially from supernovae that are closer to
<v Speaker 1>us and from those that happen much farther away. These
<v Speaker 1>additions will help refine the measurements even more. One scientist,
<v Speaker 1>Greg Aldering said they wanted to establish a solid base
<v Speaker 1>before adding several hundred more nearby supernova because this is
<v Speaker 1>the area where calibrations are most sensitive and where they've
<v Speaker 1>had the weakest data so far. He believes their new
<v Speaker 1>method lets them understand the calibration better than anyone as before,
<v Speaker 1>and they're eager to see what more supernova will reveal.
<v Speaker 1>Looking further ahead, even bigger collections of data are on
<v Speaker 1>the way. Over the next ten years. Powerful new telescopes
<v Speaker 1>like the Veri Sea Reuben Observatory in NASA's Nancy Grace
<v Speaker 1>Roman Space Telescope are expected to capture tens or even
<v Speaker 1>hundreds of thousands of new supernova With the improved analysis
<v Speaker 1>method from Union three, researchers will be ready to include
<v Speaker 1>all that data. To fully understand dark energy, scientists are
<v Speaker 1>relying on just one method. They also look at how
<v Speaker 1>galaxies form patterns using a technique called baryon acoustic oscillations
<v Speaker 1>or BAO. This method works better for studying the early universe,
<v Speaker 1>when dark energy wasn't as important yet Supernova, on the
<v Speaker 1>other hand, give very precise information about the more recent universe. Together,
<v Speaker 1>these two methods are finally becoming accurate enough to test
<v Speaker 1>different ideas about how dark energy behaves. The work is
<v Speaker 1>also a great example of how powerful scientific collaboration can be.
<v Speaker 1>At Berkeley Lab, scientists working on Supernova and others working
<v Speaker 1>on bo shared insights and helped each other improve. They
<v Speaker 1>also come bind these findings with measurements of the early
<v Speaker 1>universe's light the cosmic microwave background or CMB, to get
<v Speaker 1>an even clearer picture. All these pieces are coming together
<v Speaker 1>to help scientists understand what dark energy is, whether it
<v Speaker 1>changes over time, and what that means for the fate
<v Speaker 1>of the universe. Hidden star found orbiting Beetlejuice. Beetlejuice is
<v Speaker 1>one of the brightest stars we can see at night,
<v Speaker 1>and it's also the closest red super giant to Earth.
<v Speaker 1>It's absolutely huge. Its radius is about seven hundred times
<v Speaker 1>that of the Sun. Even though it's only about ten
<v Speaker 1>million years old, which is pretty young in space terms,
<v Speaker 1>it's already getting close to the end of its life.
<v Speaker 1>You can find Beetle Juice in the constellation Orion, where
<v Speaker 1>it forms one of the shoulders of the figure. People
<v Speaker 1>have been watching this star for thousands of years, and
<v Speaker 1>they notice that its brightness changes over time. Scientists later
<v Speaker 1>figured out that Beetlejuice two main brightness patterns, one that
<v Speaker 1>repeats roughly every four hundred days and another longer one
<v Speaker 1>that takes about six years. In twenty nineteen and twenty twenty,
<v Speaker 1>Beetlejuice suddenly got much dimmer, and many thought it was
<v Speaker 1>about to explode in a giant supernova. But it turned
<v Speaker 1>out that this great dimming happened because the star released
<v Speaker 1>a large cloud of dust that blocked some of its
<v Speaker 1>light from reaching us. That solved the mystery, but it
<v Speaker 1>made scientists much more curious about the star and inspired
<v Speaker 1>them to look at past data with fresh eyes. One
<v Speaker 1>idea that came up was that the long six year
<v Speaker 1>pattern in Beetlejuice's brightness might be caused by another star
<v Speaker 1>orbiting around it, a companion star. Astronomers used powerful telescopes
<v Speaker 1>like the Hubble Space Telescope and the Chundra X ray
<v Speaker 1>Observatory to look for this companion, but they couldn't find
<v Speaker 1>anything until now. A team led by Steve Howell, a
<v Speaker 1>scientist at NASA has finally found this companion star. They
<v Speaker 1>used a special camera called ALOPEEK, which is attached to
<v Speaker 1>a huge telescope in Hawaii called Gemini North. This camera
<v Speaker 1>uses a technique called speckle imaging, which takes super short
<v Speaker 1>snapshots to cancel out the blurring caused by Earth's atmosphere.
<v Speaker 1>With this method in the telescope's strong light collecting power,
<v Speaker 1>they were able to actually see the faint companion star
<v Speaker 1>next to Beetlejuice. By studying the light from the companion,
<v Speaker 1>Howell's team could learn more about it. It's much dimmer
<v Speaker 1>than Beetlejuice, about six times dimmer invisible light, and it's
<v Speaker 1>likely a young hot star that's still forming. It's around
<v Speaker 1>one point five times the mass of our Sun and
<v Speaker 1>hasn't even started burning hydrogen in its core yet. What's
<v Speaker 1>really impressive is how close this companion is to Beetlejuice.
<v Speaker 1>It's only about four times farther away than the distance
<v Speaker 1>between Earth and the Sun, which means it's orbiting inside
<v Speaker 1>the extended outer layers of Beetlejuice's atmosphere. This is the
<v Speaker 1>first time a star this close has been directly seen
<v Speaker 1>orbiting a super giant like Beetlejuice, and it shows just
<v Speaker 1>how powerful and precise the Gemini telescope is when paired
<v Speaker 1>with alopeek. This discovery helps scientists better understand what Beetlejuice's
<v Speaker 1>life looks like now and what will happen to it
<v Speaker 1>in the future. The two stars were likely born together,
<v Speaker 1>but the smaller companion star will have a shorter life.
<v Speaker 1>Over time, gravity will cause it to slowly spiral into
<v Speaker 1>Beetlejuice and eventually be destroyed, probably in the next ten
<v Speaker 1>thousand years. Finding this companion also helps explain why other
<v Speaker 1>red supergiants might change in brightness over long periods, something
<v Speaker 1>scientists have been curious about for a long time. Howell
<v Speaker 1>hopes that now that they've been able to detect such
<v Speaker 1>a feint and close companion, other similar discoveries might follow
<v Speaker 1>using the same method. Another scientist, Martin Still, says this
<v Speaker 1>result is a big win for the Gemini observatory, showing
<v Speaker 1>what it can do for many types of space research.
<v Speaker 1>Solving the mystery around beetlejuice that has lasted for hundreds
<v Speaker 1>of years is a major scientific achievement. The team plans
<v Speaker 1>to take more observations in twenty twenty seven, when the
<v Speaker 1>companion's star will be farthest away from Beetlejuice in its
<v Speaker 1>orbit and easier to spot again. They hope to learn
<v Speaker 1>even more during that time and continue uncovering the secrets
<v Speaker 1>of this famous star. First glimpse of rocky planets forming
<v Speaker 1>around baby star. Astronomers have managed to spot the very
<v Speaker 1>beginning of rocky planets forming around a young star that
<v Speaker 1>looks a lot like our son did long ago. This
<v Speaker 1>discovery gives scientists a rare and important look into what
<v Speaker 1>the very first stages of planet formation might have been
<v Speaker 1>like in our own Solar System billions of years ago.
<v Speaker 1>For the first time, researchers have clearly seen the hot
<v Speaker 1>area around a baby star where rocky planets like Earth
<v Speaker 1>can start to form. This moment is like a time
<v Speaker 1>zero snapshot, right when solid material first begins to appear.
<v Speaker 1>It's something scientists have been hoping to catch for a
<v Speaker 1>long time. To make this discovery, NASA's web Space telescope
<v Speaker 1>work together with a powerful set of telescopes and Chiley
<v Speaker 1>known as the European Southern Observatory. They focused on a
<v Speaker 1>very young star called Hops three point fifteen, located about
<v Speaker 1>one thousand, three hundred and seventy light years from Earth.
<v Speaker 1>It's still in its early stages of life, only about
<v Speaker 1>one hundred thousand to two hundred thousand years old, but
<v Speaker 1>it's expected to become a star like our Sun in
<v Speaker 1>space terms. That makes it practically a newborn. Because the
<v Speaker 1>star's disc of gas and dust is tilted just the
<v Speaker 1>right way, astronomers were able to see deep into it.
<v Speaker 1>They discovered tiny solid specs forming inside the hot gas,
<v Speaker 1>early signs of rock material coming together, which is how
<v Speaker 1>planets begin. They also found materials like silicon monoxide gas
<v Speaker 1>in certain kinds of hot crystals, similar to the ones
<v Speaker 1>that scientists believe were the first solid things to form
<v Speaker 1>in our Solar System back when it was just beginning
<v Speaker 1>over four point five billion years ago. Before this, no
<v Speaker 1>one had ever directly seen this type of mineral formation
<v Speaker 1>happening around young stars. Scientists weren't sure if it was
<v Speaker 1>something that always happens when planets form, or if our
<v Speaker 1>Solar System had been an unusual case. Now, this new
<v Speaker 1>observation suggests that this process might be common in the universe.
<v Speaker 1>Other studies have looked at disks of gas and dust
<v Speaker 1>around young stars, and some have seen possible signs of
<v Speaker 1>planets forming later on, but until now there hadn't been
<v Speaker 1>solid proof of that very first step, when dust starts
<v Speaker 1>becoming the building blocks of rocky planets. In a picture
<v Speaker 1>taken by the Alma Telescope Open Network in Chile, this
<v Speaker 1>forming planetary system looks like a small light shining in
<v Speaker 1>the darkness, something delicate and just beginning. It's not yet
<v Speaker 1>clear how many planets might eventually form around Hops three
<v Speaker 1>point fifteen. The gas disc surrounding the star is about
<v Speaker 1>as big as what our own Sun may have had
<v Speaker 1>long ago, so it's possible this system could end up
<v Speaker 1>with several planets, maybe even eight, like ours, though that
<v Speaker 1>would take millions of years. One of the scientists involved,
<v Speaker 1>Merril Van t Hoff, from Purdue University, hopes to study
<v Speaker 1>more young stars like this. By comparing them, astronomers might
<v Speaker 1>figure out if making Earth like planets is something that
<v Speaker 1>happens all the time in the universe, or if Earth
<v Speaker 1>is a rare exception. This discovery gives hope that planets
<v Speaker 1>like ours could be forming in many places across the galaxy,
<v Speaker 1>and maybe even worlds that could one day support life,
<v Speaker 1>Samm