The object could be an ultra-long period magnetar, a rare type of star with extremely strong magnetic fields that can produce powerful bursts of energy.

Until recently, all known magnetars released energy at intervals ranging from a few seconds to a few minutes. The newly discovered object emits radio waves every 22 minutes, making it the longest period magnetar ever detected.

The research was published today in the journal Nature.

Astronomers discovered the object using the Murchison Widefield Array (MWA), a radio telescope on Wajarri Yamaji Country in outback Western Australia.

Lead author Dr Natasha Hurley-Walker said the magnetar, named GPM J1839-10, is 15,000 light-years away from Earth in the Scutum constellation.

“This remarkable object challenges our understanding of neutron stars and magnetars, which are some of the most exotic and extreme objects in the Universe,” she said.

The stellar object is only the second of its kind ever detected after the first was discovered by Curtin University undergraduate research student Tyrone O’Doherty.

Initially, scientists could not explain what they had found.

They published a paper in Nature in January 2022 describing an enigmatic transient object that would intermittently appear and disappear, emitting powerful beams of energy three times per hour.

Dr Hurley-Walker — O’Doherty’s honours supervisor — said the first object took us by surprise.

“We were stumped,” she said. “So we started searching for similar objects to find out if it was an isolated event or just the tip of the iceberg.”

Between July and September 2022, the team scanned the skies using the MWA telescope.

They soon found what they were looking for in GPM J1839-10.

It emits bursts of energy that last up to five minutes — five times longer than the first object.

Other telescopes followed up to confirm the discovery and learn more about the object’s unique characteristics.

These included three CSIRO radio telescopes in Australia, the MeerKAT radio telescope in South Africa, the Grantecan (GTC) 10m telescope, and the XMM-Newton space telescope.

Armed with GPM J1839-10’s celestial coordinates and characteristics, the team also began searching the observational archives of the world’s premier radio telescopes.

“It showed up in observations by the Giant Metrewave Radio Telescope (GMRT) in India, and the Very Large Array (VLA) in the USA had observations dating as far back as 1988,” she said.

“That was quite an incredible moment for me. I was five years old when our telescopes first recorded pulses from this object, but no one noticed it, and it stayed hidden in the data for 33 years.

“They missed it because they hadn’t expected to find anything like it.”

Not all magnetars produce radio waves. Some exist below the ‘death line’, a critical threshold where a star’s magnetic field becomes too weak to generate high-energy emissions.

“The object we’ve discovered is spinning way too slowly to produce radio waves — it’s below the death line,” Dr Hurley-Walker said.

“Assuming it’s a magnetar, it shouldn’t be possible for this object to produce radio waves. But we’re seeing them.

“And we’re not just talking about a little blip of radio emission.

“Every 22 minutes, it emits a five-minute pulse of radio wavelength energy, and it’s been doing that for at least 33 years.

“Whatever mechanism is behind this is extraordinary.”

The discovery has important implications for our understanding of the physics of neutron stars and the behaviour of magnetic fields in extreme environments.

It also raises new questions about the formation and evolution of magnetars and could shed light on the origin of mysterious phenomena such as fast radio bursts.

The research team plans to conduct further observations of the magnetar to learn more about its properties and behaviour.

They also hope to discover more of these enigmatic objects in the future, to determine whether they are indeed ultra-long period magnetars, or something even more phenomenal.

“Two decades ago it was predicted in theory that pairs of planets of similar mass may share the same orbit around their star, the so-called Trojan or co-orbital planets. For the first time, we have found evidence in favour of that idea,” says Olga Balsalobre-Ruza, a student at the Centre for Astrobiology in Madrid, Spain who led the paper published today in Astronomy & Astrophysics.

Trojans, rocky bodies in the same orbit as a planet, are common in our own Solar System [1], the most famous example being the Trojan asteroids of Jupiter — more than 12,000 rocky bodies that are in the same orbit around the Sun as the gas giant. Astronomers have predicted that Trojans, in particular Trojan planets, could also exist around a star other than our Sun, but evidence for them is scant. “Exotrojans [Trojan planets outside the Solar System] have so far been like unicorns: they are allowed to exist by theory but no one has ever detected them,” says co-author Jorge Lillo-Box, a senior researcher at the Centre for Astrobiology.

Now, an international team of scientists have used ALMA, in which ESO is a partner, to find the strongest observational evidence yet that Trojan planets could exist — in the PDS 70 system. This young star is known to host two giant, Jupiter-like planets, PDS 70b and PDS 70c. By analysing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b’s orbit where Trojans are expected to exist.

Trojans occupy the so-called Lagrangian zones, two extended regions in a planet’s orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b’s orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our Moon might reside there.

The team believes this cloud of debris could point to an existing Trojan world in this system, or a planet in the process of forming. “Who could imagine two worlds that share the duration of the year and the habitability conditions? Our work is the first evidence that this kind of world could exist,” says Balsalobre-Ruza. “We can imagine that a planet can share its orbit with thousands of asteroids as in the case of Jupiter, but it is mind blowing to me that planets could share the same orbit.”

“Our research is a first step to look for co-orbital planets very early in their formation,” says co-author Nuria Huélamo, a senior researcher at the Centre for Astrobiology. “It opens up new questions on the formation of Trojans, how they evolve and how frequent they are in different planetary systems,” adds Itziar De Gregorio-Monsalvo, ESO Head of the Office for Science in Chile, who also contributed to this research.

To fully confirm their detection, the team will need to wait until after 2026, when they will aim to use ALMA to see if both PDS 70b and its sibling cloud of debris move significantly along their orbit together around the star. “This would be a breakthrough in the exoplanetary field,” says Balsalobre-Ruza.

“The future of this topic is very exciting and we look forward to the extended ALMA capabilities, planned for 2030, which will dramatically improve the array’s ability to characterise Trojans in many other stars,” concludes De Gregorio-Monsalvo.

Notes

[1] When asteroids in Jupiter’s orbit were first discovered, they were named after heroes of the Trojan war, giving rise to the name Trojans to refer to these objects.

The paper, published July, 19, 2023 in Nature, offers the first evidence that there is a genetic basis for asymptomatic SARS-CoV-2. The research helps to solve the mystery of why some people can be infected without ever getting sick from COVID-19. 

The secret lies with the human leukocyte antigen (HLA), or protein markers that signal the immune system. A mutation in one of the genes coding for HLA appears to help virus-killing T cells identify SARS-CoV-2 and launch a lighting attack. The T cells of some people who carry this variant can identify the novel coronavirus, even if they have never encountered it before, thanks to its resemblance to the seasonal cold viruses they already know. The discovery points to new targets for drugs and vaccines.

“If you have an army that’s able to recognize the enemy early, that’s a huge advantage,” explained the study’s lead researcher, Jill Hollenbach, PhD, MPH, professor of neurology, as well as epidemiology and biostatistics, and a member of the Weill Institute for Neurosciences at UCSF. “It’s like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys.” 

The mutation — HLA-B*15:01 — is quite common, carried by about 10% of the study’s population. It doesn’t prevent the virus from infecting cells but, rather, prevents people from developing any symptoms. That includes a runny nose or even a barely noticeable sore throat. 

UCSF researchers found that 20% of people in the study who remained asymptomatic after infection carried at least one copy of the HLA-B*15:01 variant, compared to 9% of those who reported symptoms. Those who carried two copies of the variant were far more likely — more than eight times — to avoid feeling sick.

Leveraging a national marrow donor database

Researchers suspected early on that HLA was involved, and fortunately a national registry existed that contained the data they were looking for. The National Marrow Donor Program/Be The Match, the largest registry of HLA-typed volunteer donors in the U.S., matches donors with people who need bone marrow transplants.

But they still needed to know how the donors fared against COVID-19. So, they turned to a mobile app developed at UCSF, called the COVID-19 Citizen Science Study. They recruited nearly 30,000 people who were also in the bone marrow registry and tracked through the first year of the pandemic. At that time, vaccines were not yet available, and many people were undergoing routine COVID testing for work or whenever they were potentially exposed.

“We did not set out to study genetics, but we were thrilled to see this result come from our multidisciplinary collaboration with Dr. Hollenbach and the National Marrow Donor Program,” said Mark Pletcher, MD, MPH, a professor of epidemiology and biostatistics at UCSF.

The primary study group was limited to those who self-identified as white because the final set of study respondents did not have enough people in it from other ethnic and racial groups to analyze.

Researchers identified 1,428 unvaccinated donors who tested positive between February 2020 and the end of April 2021, before the vaccines were widely available and when it still took many days to get back test results.

Of these, 136 individuals remained asymptomatic for at least two weeks before and after testing positive. Only one of the HLA variants — HLA-B*15:01 — had a strong association with asymptomatic COVID-19 infection, and this was reproduced in two independent cohorts. Risk factors for severe COVID-19, like being older, overweight and having chronic diseases like diabetes did not appear to play a role in who remained asymptomatic.   

“We are proud to partner on research that has the potential to leverage a long-term public investment in building the national registry to help cure diseases and improve our ability to avoid future pandemics,” said Martin Maiers, vice president of research at the National Marrow Donor Program/Be The Match.

To figure out how HLA-B15 managed to quash the virus, Hollenbach’s team collaborated with researchers from La Trobe University in Australia. They homed in on the concept of T-cell memory, which is how the immune system remembers previous infections. 

The researchers looked at T cells from people who carried HLA-B15 but had never been exposed to the SARS-CoV-2 virus, and found these cells still responded to a part of the novel coronavirus called the NQK-Q8 peptide. They concluded that exposure to some seasonal coronaviruses, which have a very similar peptide, called NQK-A8, enabled T cells in these individuals to quickly recognize SARS-CoV-2 and mount a faster, more effective immune response. 

“By studying their immune response, this might enable us to identify new ways of promoting immune protection against SARS-CoV-2 that could be used in future development of vaccine or drugs,” said Stephanie Gras, a professor and laboratory head at La Trobe University. 

“It felt like something out of the Lord of the Rings — like Mordor. It was hard to imagine much surviving,” said Justin Brashares, a professor of environmental science, policy and management at the University of California, Berkeley.

But mere months after the fire, animals like coyote, gray foxes and black-tailed jackrabbits were seen returning to the area, spotted by grid of motion-sensor camera traps that Brashares’ lab has operated since 2016 at the HREC, a multidisciplinary research and education facility located on the banks of the Russian River about and 13 miles south of Ukiah.

“We were surprised that many species seem to be resistant [to the impacts of the fire],” said Kendall Calhoun, a graduate student at UC Berkeley and a member of Brashares’ lab.

Calhoun is the lead author of a new study that analyzed more that 500,000 camera grid images taken at the HREC in the years before and after the Mendocino Complex Fire to understand how the blaze impacted small- and medium-sized mammals on the property.

The study, which appeared Monday in the journal Ecosphere, is one of the first studies to compare continuous wildlife observations made before and after a megafire. It is also one of a limited number of studies to focus on the impacts of megafires on California’s oak woodlands. Oak woodland ecosystems comprise a large portion of the state, and yet are underrepresented in wildfire research compared to the conifer forests of the Sierra Nevada.

“For the great majority of Californians, these oak woodlands and grassland savannahs are what we think of as the characteristic biome or ecosystem type for our state,” Brashares said. “It’s the primary ecosystem type for livestock grazing, and it’s also the primary habitat type that’s used to grow grapes for wine. It’s a critical ecosystem type, and it’s worth managing well.”

Of the eight animal species included in the study, six were found to be “resistant” to the impacts of the fire, using the area in the same ways and with approximately the same frequency as they did before the fire. These species included coyote, black-tailed jackrabbit, gray fox, racoon, striped skunk and bobcat. Western gray squirrel and black-tailed deer, however, appeared to be more vulnerable to the impacts of the fire.

Brashares and Calhoun believe many of the species were able to remain in the area thanks to small patches of tree cover spared by the fire. Photos from the camera traps reveal many animals taking refuge in these patches, using them to obtain food and resources while more heavily burned areas recovered. Some animals were even observed using these locations more often after the fire than before.

These findings highlight the importance of using techniques like grazing and prescribed burning to reduce the intensity of wildfires when they happen. These lower severity fires are more likely to leave the tree canopy intact and create the types of forest heterogeneity that can benefit fire-adapted ecosystems.

“Even this incredibly hot and devastating fire still managed to leave behind these little patches of unburnt areas, andwe were surprised at how quickly many species were able to move into those habitat patches and then spread back out into the burned areas as they recovered,” Brashares said. “This finding is very valuable for forest management because we can do things to the landscape that will increase the chance that when fire does come through, it will leave behind some of these fragments.”

An approaching inferno

Calhoun was halfway around the world visiting New Zealand when he received a text message from study co-author Kaitlyn Gaynor informing him that the HREC was on fire.

“I think my immediate text back was, ‘Is everyone okay?'” Calhoun said.

For two years, Calhoun had been helping to maintain the 36 camera traps spread across the property that had been set up in collaboration with the California Department of Fish and Wildlife to test a new way to monitor wildlife populations across the state.

Calhoun had originally joined Brashares’ lab hoping to study impacts of megafire on wildlife diversity, but the unpredictability of wildfire had made it difficult to find a study site. The Mendocino Complex Fire — while terrifying and destructive — provided him with a rare opportunity.

“From what I heard, it was really scary as the fire was coming up to the property because people live on site, so there was a big rush to evacuate. The fire ended up burning more than half of the area,” Calhoun said. “I was a continent away when I found out, but I was interested in hitting the ground running and making sure we got all the data we needed when I got back.”

Calhoun and the team first returned to the site about two months after the fire, when trees were still smoldering and the HREC resembled a “moonscape.” The team’s first task was to check on the cameras, 13 of which had been partially melted by the fire. In addition to replacing broken camera parts, they also checked to make sure the camera traps were set up at the same position and with the same orientation as they were before the fire, to ensure that their data remained as consistent as possible.

Every three months, the team visits all 36 cameras on the site, downloading the photos, ensuring that everything is working correctly and removing any grass or debris blocking the view. They then spend countless hours reviewing each shot to sort out which photos contain animals, then identify the animals and log the data.

“A lot of the data that we collect is just grass blowing in the wind,” Calhoun said.

In addition to small- and medium-sized mammals, the cameras also capture photos of larger animals, like black bears and mountain lions. Because these apex predators have huge home ranges — often many times larger than the HREC’s 5,300 acres — it is impossible to get accurate information about their distributions from the study area.

Calhoun said that, anecdotally, these animals were spotted much less frequently after the fire, suggesting that they were slower to return to the area after the blaze.

After completing his Ph.D. this summer, Calhoun plans to continue his work as a 2023 Smith Fellow, studying how broad changes in fire regimes are affecting wildlife species across California. As part of the work, he hopes to obtain broader scale data on apex predators to better understand what happens to these animals when large fires destroy their home ranges.

“For my next project, I’m really interested in looking at the broadscale effects of fire on those really wide-ranging species, like mountain lions and bears, and then also how wildfires might be impacting their relationship with people,” Calhoun said. “The conflict between bears and humans, especially in Lake Tahoe, is really big in the in the news right now, and I think that either climate change or fire might be driving some of those interactions.”

Additional study co-authors include Benjamin R. Goldstein, Kaitlyn Gaynor, Alex McInturff and Leonel Solorio of UC Berkeley. This work was supported in part by the California Department of Fish and Wildlife (CDFW Grant # P1680002) and by the NSF Graduate Research Fellowship program.

“Value isn’t just determined by an objective reward or outcome,” Collins said. “Our research suggests that people’s perception of value is largely shaped by their personal goals and the context in which the decision is made.”

For example, you might order a chocolate ice cream cone and be perfectly satisfied with your choice. But if you then find out that there’s another flavor available, you might feel less satisfied with your initial selection. In this case, the objective value of the ice cream cone hasn’t changed. What’s changed is your subjective perception of its value relative to the newfound best option, thus highlighting the impact of goal achievement on decision-making.

Using data collected from over 1,000 individuals by various laboratories, the Berkeley team has confirmed this theory by developing an “intrinsically enhanced” reinforcement learning model. While other theories propose that subjective value is simply adjusted based on different observed alternatives, the model developed by Berkeley researchers offers a new perspective: it centers around the concept that achieving a goal is crucial. The intrinsically enhanced model is not the first to examine this phenomenon, but it does provide a new way to understand the problem.

“Our study proposes a paradigm shift in how we understand decision-making,” Molinaro said. “It shows the critical importance of considering goal-dependent rewards, which may significantly alter our understanding of decision-making processes.”

The potential applications of this research are vast and varied. This new understanding could inform public policies encouraging positive behavior changes or help shape financial decisions. In an educational setting, it could be utilized to show students how learning specific topics can assist in achieving their particular goals. The research could also inform therapeutic strategies for patients suffering from mental illness or eating disorders.

This research could inspire innovation in the field of the development of artificial intelligence. “As it stands, an AI model cares primarily about extrinsic rewards,” Collins said. “Our research suggests that integrating intrinsic, goal-oriented rewards could substantially enhance these models.”

While these findings are a significant step forward in understanding decision-making processes, further research is needed to fully understand and apply this concept across various fields. The Berkeley team plans to continue exploring this important area of cognitive neuroscience.