This week in Astronomy: Dark Matter Clues, Star vs Black Hole, and Roman Telescope’s Cosmic Quest

<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. This week in Astronomy, dark
<v Speaker 1>Matter Clues, Star versus black Hole and Roman Telescope's Cosmic
<v Speaker 1>Quest Cosmic Clues. In the hunt for dark matter, scientists
<v Speaker 1>at the University of Copenhagen are trying a very unusual
<v Speaker 1>way to look for a mysterious particle called the axion.
<v Speaker 1>This particle has been discussed for decades but never actually found,
<v Speaker 1>and it could be the missing piece that explains dark matter,
<v Speaker 1>the invisible material that makes up most of the universe.
<v Speaker 1>To search for it, the researchers didn't use a laboratory
<v Speaker 1>machine like the Giant Accelerator at Cerne. Instead, they used
<v Speaker 1>nature itself, focusing on the largest magnetic fields that exist
<v Speaker 1>in galaxy clusters and the powerful light that comes from
<v Speaker 1>distant black holes. Galaxy clusters are enormous, so heavy that
<v Speaker 1>they outweigh the Sun by a quadrillion times. The axian,
<v Speaker 1>if it exists, is the complete opposite, so light that
<v Speaker 1>it is much lighter than even the smallest atom. Because
<v Speaker 1>axians could sometimes transform out of normal light when passing
<v Speaker 1>through huge cosmic magnetic fields, the researchers looked at radiation
<v Speaker 1>coming from bright galaxies, whose centers are powered by supermassive
<v Speaker 1>black holes. As the radiation traveled through the magnetic fields
<v Speaker 1>of galaxy clusters, some of it might have changed into axians,
<v Speaker 1>leaving behind tiny irregularities in the signal. The problem is
<v Speaker 1>that each irregularity is so faint it looks like random
<v Speaker 1>background noise. What of her trick was to not rely
<v Speaker 1>on just one black hole. Instead, the team observed thirty
<v Speaker 1>two supermassive black holes that happened to sit behind galaxy clusters,
<v Speaker 1>and then combined all the data. When they added the
<v Speaker 1>signals together, a strange pattern began to appear. It was
<v Speaker 1>not the definite proof of an axian, but it looked
<v Speaker 1>like the kind of signature scientists would expect if axians
<v Speaker 1>were really there. What once looked like meaningless noise began
<v Speaker 1>to resemble a clear step like shape, something the researchers
<v Speaker 1>describe as a faint cosmic whisper that has finally become
<v Speaker 1>loud enough to notice. This is still not a discovery,
<v Speaker 1>but it is a big step forward. By using this method,
<v Speaker 1>the team has been able to rule out whole regions
<v Speaker 1>where axians cannot be, which helps narrow down where to
<v Speaker 1>search next. Their experiment worked with gamma rays, but it
<v Speaker 1>can be repeated with other types of radiation such as
<v Speaker 1>X rays, which opens many new opportunities for testing. The
<v Speaker 1>most exciting part is that this technique is not limited
<v Speaker 1>to one experiment or one research group. It can be
<v Speaker 1>used again and again across many energies and situations, gradually
<v Speaker 1>filling in the puzzle of what dark matter might actually be.
<v Speaker 1>Star explodes while being swallowed by black hole. Astronomers have
<v Speaker 1>found evidence of one of the strangest explosions ever seen
<v Speaker 1>in space. They think it happened when a massive star
<v Speaker 1>was in a deadly dance with a black hole. As
<v Speaker 1>the star in the black hole orbited each other, they
<v Speaker 1>slowly got closer. The star eventually became so stressed by
<v Speaker 1>the black hole's pull that it exploded. This strange blast,
<v Speaker 1>named s N twenty twenty three ZKD might be the
<v Speaker 1>first time scientists have caught a star exploding while being
<v Speaker 1>swallowed by a black hole. The explosion was first spotted
<v Speaker 1>in July twenty twenty three thanks to an artificial intelligence
<v Speaker 1>system that scans the skuy for unusual events. Because the
<v Speaker 1>system caught it early, astronomers were able to quickly point
<v Speaker 1>many telescopes toward it, both on Earth and in space.
<v Speaker 1>That gave them a detailed record of what happened. At first,
<v Speaker 1>the explosion looked like an ordinary supernova, a bright burst
<v Speaker 1>of light when a massive star dies. But then something
<v Speaker 1>unusual happened. After fading, the explosion suddenly became bright again.
<v Speaker 1>When researchers looked back at old data, they realized the
<v Speaker 1>system had been getting slowly brighter for more than four
<v Speaker 1>years before the final blast. That long strange build up
<v Speaker 1>hinted that the star had been under intense pressure for
<v Speaker 1>a long time, probably because of the black hole pulling
<v Speaker 1>on it. The detailed data showed that the star had
<v Speaker 1>been shedding material before it exploded. When the blast finally happened,
<v Speaker 1>The first flash came from the explosion hitting thinner gas
<v Speaker 1>around it. The second later of light came from the
<v Speaker 1>blast colliding with a thicker disk of material nearby. This
<v Speaker 1>messy and unusual behavior strongly suggests that the black hole
<v Speaker 1>was influencing the star in the years before its death.
<v Speaker 1>Another possible explanation is that the black hole tore the
<v Speaker 1>star apart completely before it could explode on its own.
<v Speaker 1>In that case, the debris from the star would have
<v Speaker 1>slammed into surrounding gas and cause the light astronomers saw.
<v Speaker 1>Either way, the end result was a bigger black hole
<v Speaker 1>left behind. This event happened about seven hundred and thirty
<v Speaker 1>million light years away from Earth, but it gives scientists
<v Speaker 1>a closer look at what might be a whole class
<v Speaker 1>of rare explosions that we have never understood until now.
<v Speaker 1>It also shows how powerful AI has become as a
<v Speaker 1>tool for astronomy, since it can catch strange cosmic events
<v Speaker 1>early before they fade. With new telescopes like the Veri
<v Speaker 1>Sea Reuben Observatory soon surveying the sky every few nights,
<v Speaker 1>astronomers expect to find many more explosions like this and
<v Speaker 1>begin connecting the dots between how massive stars live and
<v Speaker 1>how they die when black holes are involved. This discovery
<v Speaker 1>was made by the Young Supernova Experiment, a project that
<v Speaker 1>uses powerful telescopes to catch new explosions as soon as
<v Speaker 1>they happen, giving astronomers the best chance to understand the
<v Speaker 1>most unusual and rare events in the universe. Roman Telescope
<v Speaker 1>will uncover the changing universe. Long ago, people thought the
<v Speaker 1>sky never really changed, except for a few bright points
<v Speaker 1>that seem to wander, which we now know are planets.
<v Speaker 1>As telescopes and detectors got better, astronomers learned that the
<v Speaker 1>universe is full of things that change over time, like
<v Speaker 1>stars exploding or black holes feeding on matter. NASA is
<v Speaker 1>preparing a new telescope, the Nancy Grace Roman Space Telescope,
<v Speaker 1>that will find a huge number of these changing events
<v Speaker 1>when it launches plan no later than twenty twenty seven.
<v Speaker 1>The Roman Telescope will be especially powerful because of how
<v Speaker 1>wide an area of the sky it can capture in
<v Speaker 1>sharp detail at once. Its main camera will see a
<v Speaker 1>region two hundred times larger than Hubble's infrared camera but
<v Speaker 1>with the same clarity. Over its first five years, Roman
<v Speaker 1>will spend most of its time on three bid projects
<v Speaker 1>chosen by the scientific community. One of these projects will
<v Speaker 1>look specifically for things that brighten, fade, or explode like
<v Speaker 1>supernova in collisions of dense stars. This part of the
<v Speaker 1>mission is called the High Latitude Time Domain Survey. It
<v Speaker 1>will focus on regions of the sky away from the
<v Speaker 1>main plane of our galaxy, where things are easier to see.
<v Speaker 1>Its main purpose is to discover tens of thousands of
<v Speaker 1>type Ia supernova. These are a special kind of exploding
<v Speaker 1>star that always reach about the same brightness at their peak.
<v Speaker 1>Because their true brightness is known, scientists can compare it
<v Speaker 1>with how dim they look from Earth to figure out
<v Speaker 1>how far away they are. ROMAN will also measure how
<v Speaker 1>fast they are moving away from us. Putting those pieces
<v Speaker 1>together will let scientists track how the universe has expanded
<v Speaker 1>at different times in its history. This is especially important
<v Speaker 1>because of dark energy, the mysterious force that is speeding
<v Speaker 1>up the expansion of the universe. Some recent studies suggest
<v Speaker 1>dark energy might even be changing over time. Roman's data
<v Speaker 1>will be crucial for testing this. The telescope will be
<v Speaker 1>able to see the faintest and most distant supernova looking
<v Speaker 1>back as far as eleven billion years, which is only
<v Speaker 1>a few billion years after the Big Bang. That would
<v Speaker 1>more than double the timeline of expansion measurements we currently
<v Speaker 1>have to find changing events. Roman will return to the
<v Speaker 1>same regions of the sky repeatedly taking pictures at different times.
<v Speaker 1>By subtracting old images from new ones, astronomers can remove
<v Speaker 1>all the stars and galaxies that don't change, leaving only
<v Speaker 1>the new events. Most of this work will happen in
<v Speaker 1>the middle of the mission, when the telescope will skin
<v Speaker 1>the same spots every five days for about two years.
<v Speaker 1>Some fields will also be checked less often over longer
<v Speaker 1>times to catch very distant events that evolve more slowly
<v Speaker 1>because of the stretching of time caused by cosmic expansion.
<v Speaker 1>This survey will also help find extremely rare explosions like
<v Speaker 1>stars completely destroyed by black holes or Parents' ability supernovae,
<v Speaker 1>which are massive blasts that leave no remnant behind. To
<v Speaker 1>catch both frequent and rare events, the survey will be
<v Speaker 1>divided into a wide part covering more area and finding
<v Speaker 1>more common events, and a deep part focusing on a
<v Speaker 1>smaller area to catch fainter and older events from up
<v Speaker 1>to ten billion years ago. The survey will observe both
<v Speaker 1>the northern and southern skies, with follow up observations from
<v Speaker 1>ground based telescopes like Subaru. ROMAN will also collect spectroscopy
<v Speaker 1>in the southern sky, which helps confirm what kind of
<v Speaker 1>supernova or transient event is being studied. Altogether, this program,
<v Speaker 1>along with roman's other large surveys, will give astronomers a
<v Speaker 1>new and detailed map of how the universe changes, going
<v Speaker 1>deeper in time and space than ever before. It will
<v Speaker 1>open the door to discovering countless unusual cosmic events and
<v Speaker 1>give scientists a clearer picture of how stars live, die,
<v Speaker 1>and shape the universe to do before n