Category: 7. Science

Stargazers in the UAE may catch an early glimpse of the Perseids meteor shower on July 24, when moonless, darker skies offer a better chance of spotting shooting stars.

While the annual showers typically dazzle in mid-August with up to 100 meteors an hour, this year’s peak will coincide with a full moon. On Thursday, however, the Moon will be not be visible, creating ideal conditions for observing celestial events such as the Perseids, active from mid-July until late August.

Khadijah Ahmed, operations manager at Dubai Astronomy Group, said the Perseids meteor shower takes place when Earth passes through the densest part of the debris trail left by Comet Swift-Tuttle.

“On July 24, the shower is still building up, so you might only see 10 to 20 meteors per hour at best, depending on your location, sky conditions and darkness,” she told The National.

“Unfortunately, there is a full moon just before the Perseid peak in August, meaning bright moonlight will wash out many meteors during the peak nights, but that’s when you typically get 60 to 100 meteors per hour under moonless conditions.”

The Perseids are one of the most anticipated meteor showers of the year, which produces bright streaks of light as the particles burn up in the atmosphere, with the most intense activity typically on August 12 and 13.

This year, however, conditions are not looking ideal because moonlight is likely to interfere with the shower’s visibility. The Dubai Astronomy Group will host a stargazing event on August 12 in Jebel Jais in Ras Al Khaimah for the public, with tickets priced at Dh200 ($54) per adult.

“We’ll focus more on stargazing, observing all the visible objects in the sky with a sideshow of the meteor,” said Ms Ahmed. “As the meteor shower will continue till late August, we might host another event depending on the weather to observe the meteors on moonless nights.”

Mohamed Usama Ismail, lead of optical astronomy and tours at Al Sadeem Astronomy in Abu Dhabi, said viewing the Perseids, whether on July 24 or during the August peak, comes down to “timing and luck”. He said visibility can vary from year to year.

“Last year, it was a bit strange,” he said. “People came to observe the Perseids on August 12 and 13 but didn’t see much. I wasn’t sure why. Then, on August 14, a group visited and saw no fewer than 50 meteors, so it’s all about luck.”

There have been reports in recent years that the Perseids’ intensity is declining and that the shower may not produce as many meteors as it once did.

Astronomers believe the showers are weaker now because thicker parts of the comet’s debris, which caused intense displays of meteors in the 1990s, have slowly spread out over time, causing fewer visible meteors today.

Al Sadeem Astronomy is not hosting a specific event for public viewing of the meteor shower, but tours of its observatory are available regularly. After the showers, the next celestial event set to take place in the UAE will be a total lunar eclipse, appearing in the skies on September 7. The Moon will pass through Earth’s shadow, turning a deep reddish colour.

“This is one of the rare astronomical events happening in the UAE in 2025,” said Ms Ahmed. “We will host an event for the eclipse and encourage everyone to witness it. You don’t need any special equipment – just go outside and look up.”

The first supermoon of the year, the Hunter’s Supermoon, will appear on October 7, followed by the Beaver on November 5 and the Cold Supermoon on December 4.

There are more meteor showers after the Perseids, including the Orionids’ peak on October 21 and 22, followed by the Leonids, peaking on November 17 and 18. The best meteor shower and often the most visible, the Geminids, will peak on December 13 and 14.

When environmental stress harms DNA, it can set off a cascade of failures linked to heart conditions, neurodegeneration, and chronic inflammation. A new chemical tool developed at UC Riverside interrupts that process, helping preserve DNA before the damage leads to disease.

The study, published in the German Chemical Society journal Angewandte Chemie International Edition, focused on mitochondrial DNA, which is separate from the DNA housed in a cell’s nucleus. While nuclear DNA contains the vast majority of the genetic code, mitochondria carry their own smaller genomes that are essential for cellular functions, including energy production. 

Mitochondrial DNA (mtDNA) exists in multiple copies per cell, but when damage occurs, these copies are often degraded rather than repaired. If left unchecked, this degradation can compromise tissue function and trigger inflammation.

The researchers developed a chemical probe that binds to damaged sites in mitochondrial DNA and blocks the enzymatic processes that lead to its degradation. This approach, rather than repairing damage, lessens the loss of mtDNA.

“There are already pathways in cells that attempt repair,” said Linlin Zhao, UCR associate professor of chemistry, who led the project. “But degradation happens more frequently than repair due to the redundancy of mtDNA molecules in mitochondria. Our strategy is to stop the loss before it becomes a problem.”

The new molecule includes two key components: one that recognizes and attaches to damaged DNA, and another that ensures it is delivered specifically to mitochondria, leaving nuclear DNA unaffected. 

“I designed the molecule by combining my expertise in chemical synthesis and the Zhao lab’s extensive experience with DNA repair and mitochondria,” said Anal Jana, a postdoctoral fellow in the Zhao lab and leading author of the study. 

In lab tests as well as studies using living cells, the probe significantly reduced mtDNA loss after lab-induced damage mimicking exposure to toxic chemicals such as nitrosamines, which are common environmental pollutants found in processed foods, water, and cigarette smoke. In cells treated with the probe molecule, mtDNA levels remained higher, which could be critical for maintaining energy production in vulnerable tissues such as the heart and brain.

Mitochondrial DNA loss is increasingly linked to a range of diseases, from multi-organ mitochondrial depletion syndromes to chronic inflammatory conditions such as diabetes, Alzheimer’s, arthritis, and inflammatory bowel disease. When mtDNA fragments escape from mitochondria into the rest of the cell, they can act as distress signals that activate immune responses.

“If we can retain the DNA inside the mitochondria, we might be able to prevent those downstream signals that cause inflammation,” Zhao said.

Importantly, the researchers found that the protected DNA remained functional, despite being chemically tagged. “We thought adding a bulky chemical might prevent the DNA from working properly,” Zhao said. “But to our surprise, it was still able to support transcription, the process cells use to turn DNA into RNA, and then into proteins. That opens the door for therapeutic applications.”

The project builds on more than two years of research into the cellular mechanisms that govern mtDNA processing. While additional studies are needed to explore clinical potential, the new molecule represents a paradigm shift.

“This is a chemical approach to prevention, not just repair,” Zhao said. “It’s a new way of thinking about how to defend the genome under stress.”

A team of scientists led by the NSF’s Green Bank Observatory (NSF GBO) recently identified an incredibly rare object known as a Long Period Radio Transient (LPT), designated CHIME J1634+44. These objects are similar to Rotating Radio Transients (RRTs), which are sources of short radio pulses believed to be caused by pulsating neutron stars (pulsars). The difference with LPTs is that they have extremely long rotation periods, often lasting between minutes and hours. However, CHIME J1634+44 is the only LPT observed to date that is spinning up, as indicated by its decreasing spin period and unusual polarization.

These attributes challenge our current understanding of transient objects and raise new questions about the physics that governs the Universe. Nevertheless, the timing of the repeating radio bursts from CHIME J1634+44 is unclear. Said Fengqiu Adam Dong, a Jansky Fellow at the NSF GBO, in a NRAO press release:

You could call CHIME J1634+44 a ‘unicorn’, even among other LPTs. The bursts seem to repeat either every 14 minutes, or 841 seconds—but there is a distinct secondary period of 4206 seconds, or 70 minutes, which is exactly five times longer. We think both are real, and this is likely a system with something orbiting a neutron star.

In addition to the Green Bank Telescope, the observations were made possible using the Very Large Array (VLA), the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Fast Radio Burst and Pulsar Project, and NASA’s Neil Gehrels Swift Observatory (Swift), with additional observations by the LOw Frequency ARray (LOFAR). The combined abilities of these telescopes allowed the scientists to detect and study the object’s unusual signals in detail.

The CHIME array, located at the Dominion Radio Astrophysical Observatory in southern British Columbia. Credit: CHIME

Whereas CHIME’s wide field of view detected the transient’s periodic bursts and monitored its spin, the VLA’s system for real-time fast transient searches using interferometric imaging (aka. realfast) provided high-frequency observations to correct for interstellar medium (ISM) distortions and offered more precise location data. The GBT contributed high-resolution timing data to analyze its polarization and spin, while Swift searched for X-ray counterparts, which complemented radio observations from the other observatories.

Normally, compacts objects like neutron stars lose energy over time, causing their spin to slow down and their spin period to grow longer. But when the team observed CHIME J1634+44, they found that its rotational period was getting shorter, meaning that LPT must be speeding up. Since there’s no plausible explanation for this occurring with a single star, the team theorizes that it must be part of a binary system with a shrinking orbit. This could be attributed to binary pairs losing energy through gravitational interaction or emitting gravitational waves (GWs).

This behavior has been seen with other closely orbiting white dwarfs, creating the illusion that their period was getting shorter, but no neutron stars have ever been found to do this with every burst. Moreover, the radio bursts from CHIME J1634+44 were traveling in a perfect swirl as they made their way through space, meaning they are entirely circularly polarized. This suggests that the way these radio waves are being produced is different from what we see in all other known objects. Said Dong:

The discovery of CHIME J1634+44 expands the known population of LPTs and challenges existing models of neutron stars and white dwarfs, suggesting there may be many more such objects awaiting discovery.

These findings open new avenues in radio astronomy and could help astronomers address the mysteries of rotating neutron stars, one of the most enigmatic objects in the cosmos.

Further Reading: NRAO

When the JWST began science observations in July 2022, it flung open a whole new window on the Universe. The JWST looked further back in time than any other telescope, and it revealed several surprises.

One of them was the Little Red Dots (LRD); ancient, faint objects that the powerful space telescope detected as far back as only 600 million years after the Big Bang.

The JWST found more than 300 LRDs, and their brightness suggested enormous stellar masses. While early thinking suggested they’re galaxies, not all agreed, and there were still many questions. There were so many LRDs at such an early time that their existence clashed with our understanding of the early cosmos.

What all scientists do seem to agree on is that these objects are quintessential to understanding the growth and evolution of the Universe into what we see today.

Related: Pushing Webb to Its Limits May Have Revealed Earliest Galaxies

Initial study showed that the LRDs are active galactic nuclei (AGN) with supermassive black holes (SMBH) in their centers. This can explain their distinct red colour, likely caused by enormous amounts of gas and dust surrounding the objects as accretion disks.

But in other respects, they don’t resemble AGN. They emit no detectable x-rays, have a flat spectrum in the infrared, and show very little variability.

New research suggests that the LRDs are not actually galaxies, but instead a type of hypothesized star called Supermassive Stars (SMS). Astronomers think that SMS are critical intermediate stages in the formation of SMBH seeds. These SMBHs power the quasars that scientists have observed in the early Universe.

The research is “Supermassive Stars Match the Spectral Signatures of JWST’s Little Red Dots.” The authors are Devesh Nandal from the Department of Astronomy at the University of Virginia, and Abraham Loeb from the Harvard and Smithsonian Center for Astrophysics. The research is available at arxiv.org.

“The James Webb Space Telescope (JWST) has unveiled a population of enigmatic, compact sources at high redshift known as “Little Red Dots” (LRDs), whose physical nature remains a subject of intense debate,” the authors write.

“Concurrently, the rapid assembly of the first supermassive black holes (SMBHs) requires the formation of heavy seeds, for which supermassive stars (SMSs) are leading theoretical progenitors.”

The researchers set out to quantitatively test the hypothesis that the LRDs are in fact primordial SMS.

SMS are thought to have around 10^6 solar masses. The idea is that these stars could only form in the early Universe, and that they exploded as core-collapse supernova that created early black holes that became seeds for SMBH. They can explain why researchers find SMBHs so early in cosmic time, long before they should exist according to current theories.

“LRDs may represent the direct photospheric light of accreting SMS caught in the final ≲ 10^3 yr before collapse,” the authors write. “This short lifetime is consistent with the rarity of LRDs, suggesting they are a fleeting but crucial phase in galaxy and black hole formation.”

The researchers developed detailed atmospheric models for an SMS with 10^6 solar masses and no metals. Since these stars are Population 3 stars, there should be contain no metals. Their model was able to account for the observed characteristics of LRDs.

The simulated SMS matched the luminosity of LRDs, and the spectral features also matched. This is critical, because, as the authors explain, “The ultimate test of our model is its ability to reproduce the observed spectra of LRDs.” For their work, they focused on two LRDs called MoM-BH*-1 and The Cliff, objects that feature prominently in scientific literature.

“A defining characteristic of the LRD spectra is the simultaneous presence of a strong, broad Hβ emission line alongside other Balmer lines in absorption,” the authors explain. They say that these are caused by the extended dense photosphere around SMSs.

Nandal and Loeb say that their work is “a first-principles investigation into whether Population III supermassive stars (SMSs) can serve as the central engines for the enigmatic class of objects known as Little Red Dots (LRDs).”

They’ve shown that SMS with 10^6 solar masses match the luminosity of LRDs. They’ve shown that an extended stellar photosphere around the SMS can account for the V-shaped Balmer break seen in LRDs. They’ve also shown that SMS spectra match the observed spectra of LRDs.

“In conclusion, our SMS model provides a remarkably simple and self-consistent physical picture for LRDs,” the authors write. While other models showing that LRDs are active galactic nuclei require separate components for emission, absorption, and continuum, theirs presents a unified origin. This is in line with Occam’s Razor, which urges us to search for explanations with the smallest number of elements.

While one study doesn’t prove anything outright, this one lays the groundwork for deeper research. “Future work should aim to build upon the foundation laid here,” the researchers write in their conclusion. Expanded models could explore whether or not their are different pathways for SMS with different masses and other properties to form the observed LRD population.

The Little Red Dots are extremely difficult to observe and are at the edge of the JWST’s capabilities. While there may be a more powerful successor to the JWST one day, for now, scientists have to work with what they’ve got.

If it is proven that the Little Red Dot galaxies aren’t galaxies at all, but are instead supermassive stars that are the progenitors of today’s supermassive black holes (SMBH), we will have an answer to one of the most compelling questions in astronomy. Scientists can continue to make the case that LRDs are actually SMS, but they may not be able to confirm until well into the future.

This article was originally published by Universe Today. Read the original article.

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Will the universe keep expanding forever, or slow down and collapse? A University of Hawaiʻi at Mānoa researcher contributed to the creation of the largest standardized collection of exploding stars, offering new clues that dark energy—which makes up about 70% of the universe and is thought to drive its accelerating expansion—might change over time.

The study, published in The Astrophysical Journal, used light from 2,087 Type Ia (pronounced “one A”) supernovae. These are powerful explosions that occur when certain types of stars die, and because they all explode in similar ways, scientists can use them like cosmic measuring sticks. Astronomers call these stellar explosions “standard candles” because their brightness is predictable, mimicking identical light bulbs scattered across the cosmos, making them perfect for measuring vast distances in space.

These explosions previously helped reveal in 1998 that the universe’s expansion is speeding up, a discovery that introduced the idea of dark energy and later earned a Nobel Prize. Since then, different experiments around the world have gathered supernova data using various tools and methods. To make the data easier to compare, researchers from the international Supernova Cosmology Project created a new dataset called Union3. It corrects for differences in how the data was collected, allowing scientists to study the universe’s expansion more precisely.

Dark energy, predicting the future of the universe

The updated analysis showed small hints that dark energy may not be constant, which challenges the current leading model based on Albert Einstein’s theory. That model assumes dark energy stays the same over time.

If dark energy changes, it could affect predictions about the future of the universe, including whether it expands forever or eventually slows down. The findings match results from another project that used a different method to study how galaxies are spread out in space, adding weight to the possibility that dark energy might evolve.

The research was a collaboration among scientists from UH, Lawrence Berkeley National Laboratory and institutions around the world. It also used computing power from UH’s high-performance cluster, Koa.

“This project shows how Hawaiʻi’s expertise and computing power can help answer some of the biggest questions in the universe,” said David Rubin, lead author, associate professor in the UH Mānoa Department of Physics and Astronomy and a leading member of the Supernova Cosmology Project. “It’s exciting that our work from Hawaiʻi is part of a global effort to unlock the secrets of dark energy.”

The Department of Physics and Astronomy is housed in UH Mānoa’s College of Natural Sciences.

For more, see this Lawrence Berkeley National Laboratory story.