Science & TechnologyS


Question

In 1952, a group of three 'stars' vanished. Astronomers still can't find them

Brian Koberlein
Universe Today
Sat, 21 Oct 2023 18:54 UTC
The vanishing of three stars
© Palomar Observatory/Solano, et alThe vanishing of three stars
On July 19, 1952, Palomar Observatory was undertaking a photographic survey of the night sky. Part of the project was to take multiple images of the same region of sky, to help identify things such as asteroids. At around 8:52 that evening a photographic plate captured the light of three stars clustered together. At a magnitude of 15, they were reasonably bright in the image. At 9:45 pm the same region of sky was captured again, but this time the three stars were nowhere to be seen. In less than an hour they had completely vanished.

Stars don't just vanish. They can explode, or experience a brief period of brightness, but they don't vanish. And yet, the photographic proof was there. The three stars are clearly in the first image, and clearly not in the second. The assumption then is that they must have suddenly dimmed, but even that is hard to accept. Later observations found no evidence of the stars to dimmer than magnitude 24. This means they likely dimmed by a factor of 10,000 or more. What could possibly cause the stars to dim by such an astounding amount so quickly?

One idea is that they are not three stars, but one. Perhaps a star happened to brighten for a short time, such as a fast radio burst from a magnetar. While this happened, perhaps a stellar-mass black hole passed between it and us, causing the flare to gravitationally lens as three images for a brief time. The problem with this idea is that such an event would be exceedingly rare, but other photographic images taken during the 1950s show similar rapid disappearances of multiple stars. In some cases, the stars are separated by minutes of arc, which would be difficult to produce by gravitational lensing.
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Galaxy

Astronomers spot record-breaking radio signal that took 8 billion years to reach Earth: "Mind-blowing"

Liam Connor
CBS
Fri, 20 Oct 2023 17:19 UTC
radio burst signal 8 billion years
© Kristi MickaligerArtist's impression of an orbital modulation model where the FRB progenitor (blue) is in an orbit with a companion astrophysical object (pink).
Scientists detect "strange" radio signal in distant galaxy

Eight billion years ago, something happened in a distant galaxy that sent an incredibly powerful blast of radio waves hurtling through the universe.

It finally arrived at Earth on June 10 last year and -- though it lasted less than a thousandth of a second -- a radio telescope in Australia managed to pick up the signal.

This flash from the cosmos was a fast radio burst (FRB), a little-understood phenomenon first discovered in 2007.

Astronomers revealed on Thursday that this particular FRB was more powerful and came from much farther away than any previously recorded, having travelled eight billion light years from when the universe was less than half its current age.
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Better Earth

Best of the Web: 3-year solar cycle anomaly during Maunder Minimum discovered in centuries-old texts from Korea

Harry Baker
Live Science
Fri, 20 Oct 2023 12:00 UTC
Korean texts solar cycle
© Yan et al. 2023An annotated section of the historical Korean texts that mentions auroras occurring during the Maunder Minimum.
Aurora records in royal chronicles from Korea show that during the 'Maunder Minimum' between 1645 and 1715, the sun's solar cycles became several years shorter than they are today.

The sun's solar cycles were once around three years shorter than they are today, a new analysis of centuries-old Korean chronicles reveals. This previously unknown anomaly occurred during a mysterious solar epoch known as the "Maunder Minimum," more than 300 years ago.

The sun is constantly in a state of flux. Our home star cycles through periods of increased activity, known as solar maximum, when solar storms become more frequent and powerful, as well as spells of reduced activity, known as solar minimum, when solar storms almost completely disappear.


Comment: According to Russian professor Valentina Zharkova, who has been warning of the hazards that accompany a 'grand solar minimum', solar storms become less frequent during a minimum but when they do happen they have the potential to be even more powerful, and harmful, than during maximum.


Comment: Notably that the current solar cycle is considered to be weaker than expected, and seems to be peaking much earlier than expected: Solar maximum could hit us harder and sooner than we thought

See also: And check out SOTT radio's:


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Info

Patients recall death experiences after cardiac arrest


NYU Langone Health
Thu, 14 Sep 2023 20:48 UTC
Brain Waves
© MARYNA IEVDOKIMOVAA new study shows some patients had brain wave patterns linked to conscious thought up to an hour after their heart stopped.
Up to an hour after their hearts had stopped, some patients revived by cardiopulmonary resuscitation (CPR) had clear memories afterward of experiencing death and while unconscious had brain patterns linked to thought and memory.

This is the finding of a study led by researchers at NYU Grossman School of Medicine, in cooperation with 25 mostly U.S. and British hospitals, in which some survivors of cardiac arrest described lucid death experiences that occurred while they were seemingly unconscious. Despite immediate treatment, less than 10 percent of the 567 patients studied, who received CPR in the hospital, recovered sufficiently to be discharged. However, 4 in 10 of those that survived recalled some degree of consciousness during CPR not captured by standard measures.

Published online September 14 in the journal Resuscitation, the study also found that in these patients, nearly 40 percent had brain activity that returned to normal, or nearly normal, at points even an hour into CPR. As captured by electroencephalogram (EEG), a technology that records brain activity with electrodes, the patients had spikes in the gamma, delta, theta, alpha, and beta waves associated with higher mental function.
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Brain

Scientists record powerful signal in the brain's white matter

Bill Snyder
Medical Express
Fri, 20 Oct 2023 19:05 UTC
signals in the brain
© agsandrew/Shutterstock
The human brain is made up of two kinds of matter: the nerve cell bodies (gray matter), which process sensation, control voluntary movement, and enable speech, learning and cognition, and the axons (white matter), which connect cells to each other and project to the rest of the body.

Historically, scientists have concentrated on the gray matter of the cortex, figuring that's where the action is, while ignoring white matter, even though it makes up half the brain. Researchers at Vanderbilt University are out to change that.

For several years, John Gore, Ph.D., director of the Vanderbilt University Institute of Imaging Science, and his colleagues have used functional magnetic resonance imaging (fMRI) to detect blood oxygenation-level dependent (BOLD) signals, a key marker of brain activity, in white matter.

Comment: With white matter comprising around 60% of brain volume, it's surprising that scientists haven't taken a bigger interest in it until lately. Just as with "junk DNA", everything in Nature is purposeful, if one pays attention.

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Chalkboard

Mathematician solves an enduring Möbius strip mystery

Rachel Crowell
Scientific American
Tue, 12 Sep 2023 16:56 UTC
Möbius strip graphic
© Dotted Yeti/Shutterstock.comThe Möbius strip has puzzled mathematicians for many years.
Möbius strips are curious mathematical objects. To construct one of these single-sided surfaces, take a strip of paper, twist it once and then tape the ends together. Making one of these beauties is so simple that even young children can do it, yet the shapes' properties are complex enough to capture mathematicians' enduring interest.

The 1858 discovery of Möbius bands is credited to two German mathematicians — August Ferdinand Möbius and Johann Benedict Listing — though evidence suggests that mathematical giant Carl Friedrich Gauss was also aware of the shapes at this time, says Moira Chas, a mathematician at Stony Brook University. Regardless of who first thought about them, until recently, researchers were stumped by one seemingly easy question about Möbius bands: What is the shortest strip of paper needed to make one? Specifically, this problem was unsolved for smooth Möbius strips that are "embedded" instead of "immersed," meaning they "don't interpenetrate themselves," or self-intersect, says Richard Evan Schwartz, a mathematician at Brown University. Imagine that "the Möbius strip was actually a hologram, a kind of ghostly graphical projection into three-dimensional space," Schwartz says. For an immersed Möbius band, "several sheets of the thing could overlap with each other, sort of like a ghost walking through a wall," but for an embedded band, "there are no overlaps like this."
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Microscope 1

Scientists finally solve mystery of why Europeans have less Neanderthal DNA than East Asian

Stephanie Pappas
Live Science
Thu, 19 Oct 2023 19:07 UTC
human and neanderthal faces
© Joe McNally / Contributor via Getty ImagesEuropeans have less Neanderthal (pictured right) ancestry than East Asians do today because farming Homo sapiens migrated from the Middle East into Europe about 10,000 years ago.
A wave of migrating farmers from the ancient Middle East may be the reason why modern Europeans don't carry as much Neanderthal DNA as today's East Asians do, a new study finds.

All humans with ancestry from outside of Africa have a little bit of Neanderthal in them — about 2% of the genome, on average. But people with East Asian ancestry have between 8% and 24% more Neanderthal genes than people of European ancestry. That's a bit of a paradox, because fossil evidence suggests Neanderthals lived in Europe. Why, then, should East Asians carry more of those genes today?

Now, a new study posits a solution to this conundrum: While a wave of human migration out of Africa before at least 40,000 years ago brought Homo sapiens — who were hunter-gatherers — into contact with their Homo neanderthalensis cousins and led to interbreeding, a later wave of H. sapiens migrating about 10,000 years ago diluted Neanderthal genes in Europe only. This was the movement of farmers with minimal Neanderthal ancestry from what is today the Middle East and southwestern Asia into Europe. These early farmers mixed with local hunter-gatherers, bringing a more H. sapiens-flavored genome to the region. The Homo sapiens who settled East Asia by around 60,000 to 70,000 years ago did not undergo this dilution from newcomers.
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Comet

City-size comet racing toward Earth regrows 'horns' after massive volcanic eruption

Harry Baker
LiveScience
Tue, 17 Oct 2023 00:00 UTC
comet
© Comet Chasers/Richard MilesComet 12P/Pons-Brook (12P) photographed Oct. 8, with visible "horns" in the comet's coma
The cryovolcanic comet 12P/Pons-Brooks, which will make its closest approach to Earth next year, has re-sprouted its distinctive "horns" after its second major eruption in four months.

An enormous volcanic comet the size of a small city has violently exploded for the second time in four months as it hurtles toward the sun. And just like the previous eruption, the cloud of ice and gas emitted what looked like a gigantic pair of horns.

The comet, named 12P/Pons-Brooks, is a cryovolcanic — or cold volcano — comet. It has a solid nucleus, with an estimated diameter of 18.6 miles (30 kilometers), and is filled with a mix of ice, dust and gas known as cryomagma. The nucleus is surrounded by a fuzzy cloud of gas called a coma, which leaks out of the comet's interior.

When solar radiation heats the comet's insides, the pressure builds up and the comet violently explodes, shooting its frosty guts out into space through large cracks in the nucleus's shell.

On Oct. 5, astronomers detected a large outburst from 12P, after the comet became dozens of times brighter due to the extra light reflecting from its expanded coma, according to the British Astronomical Association (BAA), which has been closely monitoring the comet

Comment: See also:

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Fish

This bold undersea base is planned for 2027 — can it become the 'International Space Station for the oceans'?

Rick Kazmer
Yahoo!Finance
Sun, 15 Oct 2023 08:00 UTC
Sentinel station
© DEEPSentinel underwater research station image
While many scientists are looking to the stars for exploration, experts at the United Kingdom's DEEP Research Labs are setting up habitable research stations as much as 656 feet under the sea.

It's part of a module-based habitat system in development called Sentinel that is intended to be open to public signup for various science research projects by 2027, according to a story by Interesting Engineering, which said the project was like "an International Space Station for the oceans."

Touted as a haven for underwater research, the habitat is also going to be a case study in sustainability and extended stays (for about a month) deep in the sea. The tech is designed to accommodate "six-crew, short-term deployments" up to "50-crew ... semi-permanent research stations."

It's a scenario not all that different from science fiction movie plotlines. And any "Sealab" fans out there will be amused to hear DEEP was actually founded in 2021.

Sentinel designers, however, said safety is a priority. So, barring a megalodon attack, the habitat should be an abode for research, learning, and archaeology. The goal is to form partnerships with universities and multiple nations as part of the learning experience — and surely hope they can get along better than the Sealab crew.

"DEEP represents to me the best chance we'll ever have for returning habitats to the sea floor, for peaceful purposes. Certainly, within my lifetime," John Clarke, the former head of the U.S. Naval Experimental Diving Unit, said, as quoted on DEEP's website.
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Cassiopaea

Astronomers report discovery of a supernova

Tomasz Nowakowski
Phys Org
Tue, 17 Oct 2023 18:14 UTC
Supernova SN 2021agco
© arXiv (2023). DOI: 10.48550/arxiv.2310.04827Upper panels: Early-phase images of the SN 2021agco field observed by ATLAS and the Half Meter Telescope (HMT). Lower panels: The residual images with host-galaxy template subtracted from the observed ones.
Astronomers report the discovery of a new ultrastripped supernova in the galaxy UGC 3855. The supernova was detected using the Half Meter Telescope (HMT) at the Xingming Observatory in China. The finding was detailed in a paper published October 7 on the pre-print server arXiv.

Supernovae (SNe) are powerful and luminous stellar explosions that could help us better understand the evolution of stars and galaxies. Astronomers divide supernovae into two groups based on their atomic spectra: Type I and Type II. Type I SNe lack hydrogen in their spectra, while those of Type II showcase spectral lines of hydrogen.

Type Ib supernovae (SNe Ib) are a subclass of stripped-envelope core-collapse SNe. They are formed when a massive star, with its outer envelope of hydrogen stripped away, collapses under its own gravity. Moreover, astronomers also distinguish ultrastripped-envelope SNe (USSNe), showing spectral features similar to those of SNe Ib/Ic, but relatively faint. In these rare SNe, the progenitor envelope has been extremely stripped before explosion.

Now, a team of astronomers led by Shengyu Yan of the Tsinghua University in Beijing, China, reports the finding of a peculiar Type Ib USSNe. The supernova was first identified with HMT on December 5, 2021 and received designation SN 2021agco.

"In this paper, we present the discovery and study of a new ultrastripped supernova, SN 2021agco," the researchers wrote.
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