Latest news with #NICER
Yahoo
16-04-2025
- Science
- Yahoo
Long-dormant black hole 'woke up' before our eyes — now, it's doing something that astronomers can't explain
When you buy through links on our articles, Future and its syndication partners may earn a commission. In December 2019, an ordinary galaxy 300 million light-years from us in the constellation Virgo suddenly woke up. After decades of inactivity, the black hole at the galaxy's heart burst with light. Now, the cosmic monster appears to be doing something that is forcing astronomers to re-evaluate their understanding of these massive celestial bodies. The black hole now gives off powerful X-rays at nearly regular intervals. These outbursts are known as quasi-periodic eruptions (QPEs), and have been observed emitting from other black holes. But the bursts observed here are up to 100 times more powerful than normal, according to new research. First observed in February 2024 by astronomers at Valparaiso University in Chile, this behavior grants scientists an unprecedented view of a black hole that seems to be awakening from dormancy with no sign of going back to sleep. Led by the Valparaiso team, a group of researchers published their observations of the black hole's QPE in a study on April 11 in the journal Nature Astronomy. In addition to giving astronomers a novel view of black holes, these events are also spurring researchers to reconsider how black holes behave. "This is the first time we have observed such an event in a black hole that seems to be waking up," the paper's first author Lorena Hernández-García, an astronomy researcher at Valparaiso University, said in a statement. "This rare event provides an opportunity for astronomers to observe a black hole's behaviour in real time." Related: Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it The galaxy, called SDSS1335+0728, first called attention to itself in 2019 when it unexpectedly started gleaming. At that time, astronomers from the European Southern Observatory studied the event by consulting NASA's Swift X-ray space telescope and data from the eROSITA X-ray telescope. After investigating the galaxy's central region — nicknamed Ansky — they concluded that the flash resulted from Ansky's massive black hole beginning an active phase. But in February 2024, Hernández-García's team noticed bursts of previously undetected X-rays emanating from Ansky, caught by X-ray space telescopes XMM-Newton and NASA's NICER, Chandra, and Swift. These QPEs are momentary, recurring X-ray flares. Astronomers believe QPEs result from interaction between accretion disks — the swirling ring of red-hot matter that surrounds a black hole — and nearby objects, like a star or a smaller black hole. But Ansky's QPEs aren't typical. They're remarkable because they last 10 times longer and are 10 times more luminous than average QPEs, the researchers said. Persisting for more than four days, they each release one hundred times more energy than what's expected. These QPEs reveal a whole new aspect of black holes that don't fit neatly into astronomers' prior understanding of the cosmic bodies. In particular, these unusual QPEs can help broaden our understanding of how these events occur. For example, there's no evidence that Ansky has shredded a star into its accretion disk, which is what researchers currently believe triggers most QPEs. Therefore, there must be another explanation for the impetus that causes the QPEs in this case. The X-ray bursts may instead come from energetic shocks in the accretion disk spurred by a small celestial object repeatedly disrupting its orbiting material, according to the paper. RELATED STORIES —Incredible photo shows supermassive black hole blowing a jet of matter into interstellar space —Black holes can destroy planets — but they can also lead us to thriving alien worlds. Here's how. —Black holes may obey the laws of physics after all, new theory suggests It's also possible that these repeated QPEs come from gravitational waves. The European Space Agency's upcoming Laser Interferometer Space Antenna (LISA), set to launch in 2035, may confirm that connection by detecting gravitational waves with greater fidelity than ever before. For now, Ansky is reshaping how we conceive of black holes. "Studying Ansky will help us to better understand black holes and how they evolve," Hernández-García said.
Yahoo
18-03-2025
- Science
- Yahoo
How did Nasa's Suni and Butch fill nine months in space?
Voting, enjoying Christmas dinner and keeping fit in zero gravity - that's just some of what has kept Butch Wilmore and Suni Williams busy during their prolonged stay on the International Space Station (ISS). After nine months, the pair are finally making their way home in a SpaceX Dragon capsule. So what has life been like for the Nasa astronauts orbiting 250 miles (400km) above us, and how have they passed the time? Astronauts reveal what life is like on ISS – and how they deal with 'space smell' Of course there was a lot of serious space stuff to keep them occupied. Suni, 59, and Butch, 62, have been helping ongoing missions at the station with maintenance and experiments, and have conducted spacewalks. Suni ventured outside in mid-January with fellow astronaut Nick Hague to perform repairs on the craft. She and Butch went out together later in the month. Their tasks included repairing equipment that governs station orientation, adding light filters on the NICER X-ray telescope, and replacing a reflector device on an international docking adapter. Butch and Suni have taken the situation in their stride, saying in a news conference in September that they have been trained to "expect the unexpected". They have definitely had opportunities for reflection about life back home - and for watching a lot of sunrises and sunsets. As the space station makes 16 orbits of Earth every 24 hours, it travels through 16 sunrises and sunsets, treating those on board to a sunrise or sunset every 45 minutes. Living with such a unique view of the Earth gives plenty of room for contemplating it, something Suni has acknowledged. "It opens up the door to making you think a bit differently. It's the one planet we have and we should be taking care of it," she said. "There are so many people on Earth sending us messages it makes you feel right at home with everybody." Butch and Suni and the two other Americans who were on board with them, Don Pettit and Nick Hague, each had the opportunity to vote in last year's US election. "It's a very important duty that we have as citizens," Suni said to reporters. Butch said Nasa had made it "very easy" for them to be included in elections. To facilitate their voting, the Mission Control Center in Houston sent ballot papers via encrypted email to the ISS. The astronauts then filled them out and transmitted them to satellites which relayed them to a ground terminal in New Mexico. From there, landlines transmitted the ballots to Mission Control, who then electronically sent them to the astronauts' county clerks for filing. For Butch, the day starts at 04:30, and as for Suni, she makes a slightly kinder 06:30 start. Both have said they enjoy the two hours or more of exercise they must do daily to combat the loss of bone density from living in space. "Your joints don't hurt, which is quite nice," Butch has said. Three different machines help to counter the effect of living in zero gravity. The Advanced Resistive Exercise Device (ARED) is used for squats, deadlifts, and rows that work all the muscle groups. For treadmills crews must strap in to stop themselves floating away, and there is also a cycle ergometer for endurance training. At Christmas, astronauts on the International Space Station posted a festive message in which they wished their friends and family on Earth a merry Christmas. The team dressed in Santa hats and reindeer antlers, throwing the slowly gyrating microphone to each other to speak while candy canes floated around their heads. It was a chance for the crew to let their hair down, though in Suni's case it was more a case of letting it 'up'. Zero gravity has given her a style that would take a lot of product to achieve on Earth. To everyone on Earth, Merry Christmas from our @NASA_Astronauts aboard the International @Space_Station. — NASA (@NASA) December 23, 2024 One of Butch and Suni's final duties on board the ISS was to make their replacements feel welcome. On 16 March a SpaceX capsule carrying a new crew arrived at the ISS. It was a deeply significant event for Butch and Suni, as it paved the way for them to come home. Capturing the excitement, Don Pettit, who will remain on the ISS, posted this video shot through the window of it approaching and docking. Crew 10 Dragon vehicle arriving! — Don Pettit (@astro_Pettit) March 16, 2025 Butch rang a ceremonial bell as Suni handed over command to cosmonaut Alexei Ovchinin.
Yahoo
18-03-2025
- Science
- Yahoo
How did Nasa's Suni and Butch fill nine months in space?
Voting, enjoying Christmas dinner and keeping fit in zero gravity - that's just some of what has kept Butch Wilmore and Suni Williams busy during their prolonged stay on the International Space Station (ISS). So what has life been like for the Nasa astronauts orbiting 250 miles (400km) above us, and how have they passed the time? Astronauts reveal what life is like on ISS – and how they deal with 'space smell' Of course there was a lot of serious space stuff to keep them occupied. Suni, 59, and Butch, 62, have been helping ongoing missions at the station with maintenance and experiments, and have conducted spacewalks. Suni ventured outside in mid-January with fellow astronaut Nick Hague to perform repairs on the craft. She and Butch went out together later in the month. Their tasks included repairing equipment that governs station orientation, adding light filters on the NICER X-ray telescope, and replacing a reflector device on an international docking adapter. Butch and Suni have taken the situation in their stride, saying in a news conference in September that they have been trained to "expect the unexpected". They have definitely had opportunities for reflection about life back home - and for watching a lot of sunrises and sunsets. As the space station makes 16 orbits of Earth every 24 hours, it travels through 16 sunrises and sunsets, treating those on board to a sunrise or sunset every 45 minutes. Living with such a unique view of the Earth gives plenty of room for contemplating it, something Suni has acknowledged. "It opens up the door to making you think a bit differently. It's the one planet we have and we should be taking care of it," she said. "There are so many people on Earth sending us messages it makes you feel right at home with everybody." Butch and Suni and the two other Americans who were on board with them, Don Pettit and Nick Hague, each had the opportunity to vote in last year's US election. "It's a very important duty that we have as citizens," Suni said to reporters. Butch said Nasa had made it "very easy" for them to be included in elections. To facilitate their voting, the Mission Control Center in Houston sent ballot papers via encrypted email to the ISS. The astronauts then filled them out and transmitted them to satellites which relayed them to a ground terminal in New Mexico. From there, landlines transmitted the ballots to Mission Control, who then electronically sent them to the astronauts' county clerks for filing. For Butch, the day starts at 04:30, and as for Suni, she makes a slightly kinder 06:30 start. Both have said they enjoy the two hours or more of exercise they must do daily to combat the loss of bone density from living in space. "Your joints don't hurt, which is quite nice," Butch has said. Three different machines help to counter the effect of living in zero gravity. The Advanced Resistive Exercise Device (ARED) is used for squats, deadlifts, and rows that work all the muscle groups. For treadmills crews must strap in to stop themselves floating away, and there is also a cycle ergometer for endurance training. At Christmas, astronauts on the International Space Station posted a festive message in which they wished their friends and family on Earth a merry Christmas. The team dressed in Santa hats and reindeer antlers, throwing the slowly gyrating microphone to each other to speak while candy canes floated around their heads. It was a chance for the crew to let their hair down, though in Suni's case it was more a case of letting it 'up'. Zero gravity has given her a style that would take a lot of product to achieve on Earth. One of Butch and Suni's final duties on board the ISS was to make their replacements feel welcome. On 16 March a SpaceX capsule carrying a new crew arrived at the ISS. It was a deeply significant event for Butch and Suni, as it paved the way for them to come home. Capturing the excitement, Don Pettit, who will remain on the ISS, posted this video shot through the window of it approaching and docking. Butch rang a ceremonial bell as Suni handed over command to cosmonaut Alexei Ovchinin.
Yahoo
11-02-2025
- Science
- Yahoo
What was the mysterious space signal scientists discovered in 2024? Here are some possibilities
When you buy through links on our articles, Future and its syndication partners may earn a commission. Having launched on January 9, 2024 by the Chinese Academy of Sciences, the Einstein Probe detected several new events during its commissioning phase. Last October, Yuan Weimin, the spacecraft's principle investigator, told China Central Television that the X-ray observatory had already discovered around 60 very strong transient celestial objects, close to a thousand potential transients, and nearly 500 stellar flares, along with a gamma-ray burst from the very early universe. One of those detections was EP240408a, an unusual blast that lit up discussions between astronomers. Zhang and his colleagues immediately utilized the spacecraft's second instrument, the Follow-up X-ray Telescope, to take observations of the new source 1.8 days after it was first spotted by its companion, the Wide-field X-ray Telescope. Both teams of researchers sprung into action, requesting time on Earth- and space-based instruments in a multitude of wavelengths. Together, the two research groups pointed almost 20 different telescopes besides the Einstein Probe at the new incident, spanning optical, radio, gamma ray, ultraviolet and near-infrared wavelengths. Most of those instruments saw nothing. And that's unusual. Known X-ray emitters tend to be of the multiwavelength sort, sending out signals in more than one regime. Zhang and his colleagues only saw the EP240408a shine in the X-ray, while O'Connor identified a possible optical counterpart: a small, faint galaxy that may be where the signal emerged. That's not the only way that EP240408a doesn't fit with the existing transient models. The new explosion lit up X-rays for somewhere between seven and 23 days, an estimate based on when EP was pointed in its direction. Fast X-ray bursts, intense short explosions resulting from violent processes, flare anywhere from sub-seconds to hundreds of seconds before they disappear. Longer transients associated with galactic nuclei last anywhere from months to years. The unusual mid-range sets EP240408a apart. Additionally, the new target fired off a 12-second flare 300 times brighter than the underlying X-ray emission before fading to the lower levels. NASA's Neutron star Interior Composition Explorer (NICER) was one of the few instruments able to catch a glimpse of EP's newest hit. "Once we realized that EP240408a was a compelling new transient, we requested NICER pointings," Francesco Zelati, a researcher at the Institute of Space Sciences and part of the Zhang group, told by email. Zelati and his colleagues used the International Space Station-based X-ray observatory to better characterize the new event's X-ray properties and capture any rapid changes in its emission. NICER was one of the few instruments able to detect the brief event both because of its high collecting area and its flexible scheduling. "Many other observatories either lack the rapid scheduling or the sensitivity in the relevant energy ranges," Zelati said. NICER's quick response allowed it to obtain data that was "key to track the evolution of the transient," he said. Both teams also relied on detection by NASA's Neil Gehrels Swift Observatory (Swift) in the X-ray. In addition to measuring the signal, Zhang said that the spacecraft helped to narrow down the location of the source. O'Connor used Swift's measure of hydrogen, the primordial gas that is the building material for everything in the universe, to determine that the explosion came from outside the Milky Way. Their findings led them to infer hydrogen is absorbing the X-ray photons in the far-off host galaxy. Both teams turned a variety of optical telescopes towards the flare. With the Gemini South Observatory, based in Chile, O'Connor identified a faint galaxy that could be home to the event. The two independent teams of astronomers compared their measurements and came to slightly different conclusions. O'Connor and his colleagues suspect that the distant explosion may be an event known as a tidal disruption event, or TDE. A TDE occurs when a star passes dangerously close to a black hole and is shredded by its gravitational forces. Only a hundred TDEs have been discovered since the first was spotted in 1995. In extremely rare cases, the black hole's tidal forces fire material outward in a high-velocity jet that interacts with nearby material, shining brightly in both X-ray and radio wavelengths. Only four TDEs to date are thought to have relativistic jets — and the X-ray signal is very similar to those four. But observations in radio frequencies with multiple telescopes have come up empty. To Zhang, that omits jetted TDEs from consideration. "It is hard to explain EP240408a with jet [TDE] due to the lack of low-frequency — radio to near-infrared — radiation of the source," he said. His coauthor, Zelati, isn't so quick to dismiss the results. It's possible that radio or longer-wavelength emission would appear later, when the jet expands into the surrounding medium. "This radio-bright phase could emerge anywhere from weeks to many months after the initial event," he said. O'Connor and his colleagues had the same thought. They suspect that the jet may take some time to decelerate, delaying the shockwave that would spark radio emissions. "Such delayed late time radio emission has been observed in many past TDEs recently over a range of timescales," he said. "It appears to be an almost ubiquitous property." It's the timescale that is a challenge to explain, he said. While EP240408a has a similar appearance to other relativistic jetted TDEs, the X-ray signal decays more rapidly. "Such a short timescale can be possible if the black hole is quite small and the star quite dense," O'Connor says. "We favored an intermediate mass black hole disrupting a white dwarf." Zhang and colleagues suspect that the unusual signal may instead be an entirely new class of object. "We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of about 10 days, that may have been missed in previous time-domain surveys," they wrote in their paper. That could be because intermediate-length X-ray transients could go unnoticed in surveys focusing on either very long-scale objects or extremely short bursts, Zelati said. O'Connor and his coauthors don't rule out a brand new class of object. Pointing out in their research that the observed properties of EP240408a "do not directly align with any known transient class," they admit that a jetted TDE does not perfectly explain the observations. "The alternative is that EP240408a may represent a new, previously unknown class of transient," they wrote. Related Stories: — X-rays reveal secret gas in huge and distant galaxy cluster — X-ray spacecraft reveals odd 'Cloverleaf' radio circle in new light (image) — Record-breaking radio burst could help us find the universe's missing matter "Discovering a new class of intermediate X-ray transients like EP240408a would significantly enhance our comprehension of the diverse and dynamic processes in the universe," Zelati said. Such a discovery would fill in gaps of classifications of X-ray phenomena, potentially leading to the development of new theories and observational studies to find more like it. "Ultimately, it would broaden our understanding of high-energy astrophysical events," he said. It's extremely likely that the Einstein Probe will most likely detect similar events throughout its mission, assuming it hasn't already. "Future detections of similar events by EP will help us figure this out as a community," O'Connor wrote. "I am definitely looking forward to the weird transients EP will discover in the future!"
