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Astronomers Just saw the Most Powerful Gamma-ray Burst Ever Recorded

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Gamma-ray bursts (GRBs) are one of the most mysterious transient phenomena facing astronomers today. These incredibly energetic bursts are the most powerful electromagnetic events observed since the Big Bang and can last from a few milliseconds to many hours. Whereas longer bursts are thought to occur during supernovae, when massive stars undergo gravitational collapse and shed their outer layer to become black holes, shorter events have also been recorded when massive binary objects (black holes and neutron stars) merge.

These bursts are characterized by an initial flash of gamma rays and a longer-lived “afterglow” typically emitted in X-ray, ultraviolet, radio, and other longer wavelengths. In the early-morning hours on October 14th, 2022, two independent teams of astronomers using the Gemini South telescope observed the aftermath of a GRB designated GRB221009A. Located 2.4 billion light-years away in the Sagitta constellation, this event was perhaps the closes and most powerful explosion ever recorded and was likely triggered by a supernova that gave birth to a black hole.

 

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Longer-duration GRBs occur when massive stars go supernova, producing a remnant black hole and blowing off their outer layers. The force of this explosion creates powerful jets as ejected material is accelerated to nearly the speed of light, pushing through debris and emitting X-rays and gamma-rays as they reach further into space. If these jets travel in the general direction of Earth, astronomers will observe them as bright flashes of X-rays and gamma-rays. Using data from some of the most powerful telescopes on Earth and in space, astronomers were able to make unprecedented observations of a nearby GRB.

GRB221009A was first detected on the morning of October 9th, 2022, by X-ray and gamma-ray space telescopes – including NASA’s Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and the Wind spacecraft. Almost immediately after, observatories worldwide raced to conduct follow-up observations and determine what resulted. Using the Gemini South telescope (operated by NOIRLab), two independent teams made rapid Target of Opportunity (ToO) observations of the powerful event’s afterglow.

The teams were led by Brendan O’Connor, a graduate observational astronomer with the University of Maryland and George Washington University, and Jillian Rastinejad, a Ph.D. student at Northwestern University’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). The two teams obtained the earliest-possible observations of the afterglow mere minutes apart using the Gemini South’s FLAMINGOS-2 near-infrared imaging instrument and the Gemini Multi-Object Spectrograph (GMOS), respectively.

As Rastinejad explained in a recent NOIRLab’s press release, their combined datasets produced an image of what could be the brightest GRB ever observed:

“In our research group, we’ve been referring to this burst as the ‘BOAT,’ or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart. Gemini’s sensitivity and diverse instrument suite will help us to observe GRB221009A’s optical counterparts to much later times than most ground-based telescopes can observe. This will help us understand what made this gamma-ray burst so uniquely bright and energetic.

The speed with which the teams made their observations is a testament to the Gemini Observatory’s infrastructure and data-reduction software – including the Fast Initial Reduction Engine (FIRE) and Data Reduction for Astronomy from Gemini Observatory North and South (DRAGONS) platforms. Shortly after, the NASA Gamma-ray Coordinates Network began filling up with reports from observatories worldwide. Based on the available data, scientists believe that the GRB was the result of a collapse of a star many times the mass of our Sun that gave birth to a black hole.

Artistic representation of two merging neutron stars. Credit: Dana Berry, SkyWorks Digital, Inc.

What’s more, the data from this event may help resolve an ongoing mystery regarding GRBs. Whereas most gamma-ray bursts have been observed in distant galaxies, some appear as lonely flashes from intergalactic space. This has raised questions about the true origins and distances of GRBs, with many astronomers theorizing that certain short bursts originate in the intergalactic medium (IGM). However, these results suggest that short GRBs may have been more common in the past than expected.

The research teams came to this conclusion after consulting data on the 120 short GRBs observed by the two main instruments aboard NASA’s Neil Gehrels Swift Observatory – the Burst Alert Telescope (BAT) and the Swift X-ray Telescope, which detect bursts and examine the X-ray afterglow. They paired this with additional afterglow studies made with the Lowell Discovery Telescope (LDT), which found that 43 of the short GRBs were not associated with any known galaxy and appeared in the comparatively empty space between galaxies. As O’Connor explained in a University of Maryland news story:

“Many short GRBs are found in bright galaxies relatively close to us, but some of them appear to have no corresponding galactic home. By pinpointing where the short GRBs originate, we were able to comb through troves of data from observatories like the twin Gemini telescopes to find the faint glow of galaxies that were simply too distant to be recognized before.”

These findings could also have implications for our understanding of the early Universe. In recent years, astronomers have found evidence that precious metals like gold and platinum may have come from neutron star mergers that happened billions of years ago. If these events were more common in the past, it could mean that the Universe was seeded with precious metals earlier than expected. In the meantime, the energetic nature of this event makes it a once-in-a-lifetime opportunity for astronomers. As O’Conner explained:

“The exceptionally long GRB 221009A is the brightest GRB ever recorded and its afterglow is smashing all records at all wavelengths. Because this burst is so bright and also nearby, we think this is a once-in-a-century opportunity to address some of the most fundamental questions regarding these explosions, from the formation of black holes to tests of dark matter models.

Artist’s impression of two neutron stars colliding, known as a “kilonova” event. Credits: Elizabeth Wheatley (STScI)

Because of its relative proximity to Earth, this event is also a unique opportunity to study the origin of the elements heavier than iron (which form in the interiors of stars) and whether they come from neutron-star mergers alone or collapsing stars as well. Last, but not least, this event also led to disturbances in the Earth’s ionosphere that affected long-wave radio transmissions and produced very high-energy (18 tera-electron-volt) photons detected by the Chinese Large High Altitude Air Shower Observatory.

How these photons survived the 2.4 billion-year journey to Earth is a mystery. Therefore, this data could reveal new insight into how the laws of physics behave in extreme circumstances and allow astrophysics to predict the effect that future GRBs could have on Earth.

The International Gemini Observatory consists of the Gemini North Telescope in Hawaii and the Gemini South Telescope in Chile, which are operated by the National Optical-Infrared Astronomy Research Laboratory (NOIRLab) – part of the National Science Foundation’s (NSF). The papers that describe the two teams’ findings recently appeared in the Monthly Notices of the Royal Astronomical Society and The Astrophysical Journal.

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New branch on tree of life includes ‘lions of the microbial world’

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There’s a new branch on the tree of life and it’s made up of predators that nibble their prey to death.

These microbial predators fall into two groups, one of which researchers have dubbed “nibblerids” because they, well, nibble chunks off their prey using tooth-like structures. The other group, nebulids, eat their prey whole. And both comprise a new ancient branch on the tree of life called “Provora,” according to a paper published today in Nature.

Microbial lions

Like lions, cheetahs, and more familiar predators, these microbes are numerically rare but important to the ecosystem, says senior author Dr. Patrick Keeling, professor in the UBC department of botany. “Imagine if you were an alien and sampled the Serengeti: you would get a lot of plants and maybe a gazelle, but no lions. But lions do matter, even if they are rare. These are lions of the microbial world.”

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Using water samples from marine habitats around the world, including the coral reefs of Curaçao, sediment from the Black and Red seas, and water from the northeast Pacific and Arctic oceans, the researchers discovered new microbes. “I noticed that in some water samples there were tiny organisms with two flagella, or tails, that convulsively spun in place or swam very quickly. Thus began my hunt for these microbes,” said first author Dr. Denis Tikhonenkov, senior researcher at the Institute for Biology of Inland Waters of the Russian Academy of Sciences.

Dr. Tikhonenkov, a long-time collaborator of the UBC co-authors, noticed that in samples where these microbes were present, almost all others disappeared after one to two days. They were being eaten. Dr. Tikhonenkov fed the voracious predators with pre-grown peaceful protozoa, cultivating the organisms in order to study their DNA.

“In the taxonomy of living organisms, we often use the gene ’18S rRNA’ to describe genetic difference. For example, humans differ from guinea pigs in this gene by only six nucleotides. We were surprised to find that these predatory microbes differ by 170 to 180 nucleotides in the 18S rRNA gene from every other living thing on Earth. It became clear that we had discovered something completely new and amazing,” Dr. Tikhonenkov said.

New branch of life

On the tree of life, the animal kingdom would be a twig growing from one of the boughs called “domains,” the highest category of life. But sitting under domains, and above kingdoms, are branches of creatures that biologists have taken to calling “supergroups.” About five to seven have been found, with the most recent in 2018 — until now.

Understanding more about these potentially undiscovered branches of life helps us understand the foundations of the living world and just how evolution works.

“Ignoring microbial ecosystems, like we often do, is like having a house that needs repair and just redecorating the kitchen, but ignoring the roof or the foundations,” said Dr. Keeling. “This is an ancient branch of the tree of life that is roughly as diverse as the animal and fungi kingdoms combined, and no one knew it was there.”

The researchers plan to sequence whole genomes of the organisms, as well as build 3D reconstructions of the cells, in order to learn about their molecular organization, structure and eating habits.

International culture

Culturing the microbial predators was no mean feat, since they require a mini-ecosystem with their food and their food’s food just to survive in the lab. A difficult process in itself, the cultures were initially grown in Canada and Russia, and both COVID and Russia’s war with Ukraine prevented Russian scientists from visiting the lab in Canada in recent years, slowing down the collaboration.

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How A Hellish Planet Made Of Diamonds Covered By A Lava Ocean Got Where It Is Today

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In recent decades it’s become clear that the universe is teeming with planets and astronomers have begun to catalog them by the hundreds. Most of the worlds we’ve discovered so far are remarkably inhospitable and the closer we look at some, the more hellacious they seem to appear.

Case in point is 55 Cancri e, also known as 55 Cnc or by its nickname, Janssen. This world orbits so close to its star, known as Copernicus or 55 Cnc, that a year on its surface passes in only 18 hours and temperatures can soar over 4,000 degrees Fahrenheit.

Enduring such extreme conditions for so long has led scientists to suggest that the scalding world could have an interior full of diamonds, covered by a surface ocean of molten lava.

Makes Mauna Loa seem almost minor league on the cosmic scale of volcanism.

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There’s a reason that we keep spotting so many relatively hot planets next to their stars. Call it an inherent bias of our existing tech: it’s just easier to see planets orbiting close in to their stars.

In fact, most exoplanets discovered and cataloged so far have a very good chance of being so-called “hot Jupiters” — giant planets orbiting close-in. Being massive and next to your local source of light makes you especially easy to spot.

So 55 Cancri e is actually an important exoplanet as one of the first small, rocky planets found orbiting extremely close to its star.

Now researchers have made use of a new tool called EXPRES (for EXtreme PREcision Spectrometer) at the Lowell Discovery Telescope in Arizona to make ultra-precise measurements that helped them determine the orbit of this hellish world in more detail.

They found that the planet orbits Copernicus right along the equator of the star and that it likely originally orbited further out and was slowly pulled into its current alignment by the gravitational pull of the star and other objects in the unusual star system.

The system is located only 40 light years from Earth and consists of main-sequence star Copernicus paired with a red dwarf star. The binary duo also count at least five exoplanets that all have very different orbits among their cosmic family.

The new research, led by Lily Zhao at Flatiron Institute’s Center for Computational Astrophysics and published in Nature Astronomy, posits that the interactions between these oddball family members shifted Janssen to its current, insufferable orbit.

Although it was pushed, pulled and prodded into its current position, Zhao says that even in its original orbit, the planet “was likely so hot that nothing we’re aware of would be able to survive on the surface.”

What a waste of so much diamond.

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Rare Mars eclipse by the full moon wows stargazers with occultation

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On Wednesday (Dec. 7), skywatchers around the world were treated to a celestial show as the full moon eclipsed Mars in the night sky.

The rare event, known as a lunar occultation, refers to one celestial body — in this case, Mars — appearing to disappear or hide behind another — in this case, the moon. This occultation was particularly noteworthy because Mars was at opposition, meaning Earth was directly between it and the sun, making the Red Planet appear particularly bright in the night sky.

Last night’s occultation of Mars by the full moon produced some gorgeous images from observers around the world. The Griffith Observatory in California had a great view of the moon and Mars joining up on Dec. 7 and caught a time-lapse of the Red Planet disappearing behind Earth’s celestial companion as seen in the video above.

In addition, skywatchers around the world have been posting gorgeous images of the lunar occultation of Mars on social media, offering a look at one of the year’s most-watched celestial events.

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Astrophotographer Andrew McCarthy caught Mars and the full moon (opens in new tab) in a beautiful close-up:

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Spaceflight photographer John Kraus caught a stunning shot of Mars (opens in new tab) as it appeared behind the moon following occultation:

Amateur astrophotographer Tom Williams produced a gorgeous image of the moon and Mars by combining multiple photographs, and offered an explanation of how he made the image (opens in new tab) on Twitter.

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Amateur astronomer and photographer Tom Glenn produced a breathtaking image of Mars (opens in new tab) rising above the moon by stacking 15 different photograph frames.

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Astronomer and science communicator Phil Plait caught Mars creeping behind the moon (opens in new tab) just prior to occultation.

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The lunar occultation of Mars by the full Cold Moon was particularly noteworthy because the Red Planet only appears at opposition every 26 months, so the next opposition won’t occur until January 2025.

Mars was also especially close to Earth during this event, which occurred while the planet was at perigee, or its closest point to Earth in its orbit. The record for closest approach between Mars and Earth was set in 2003 at just 34.8 million miles (56 million kilometers); according to NASA, Mars and Earth won’t be this close for another 265 years, until 2287.

Editor’s Note: If you snap a great photo of either Mars at opposition or the lunar occultation and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com

Editor’s Note: This piece was updated at 4:30 p.m. EST (2130 GMT) on Dec. 8 to indicate that the record for Mars’ closest approach to Earth was set in 2003.

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