(Press-News.org) For the first time, astronomers have observed radio waves emitted by a Type Ia supernova, a type of explosion originating from a white dwarf star. This provides important clues to understand how white dwarfs explode.
A Type Ia (One-A) supernova is the nuclear explosion of a white dwarf star. This type of supernova is well known; these supernovae are used by astronomers to measure cosmological distances and the expansion of the Universe. But the explosion mechanism of Type Ia supernovae is not well understood. Solitary white dwarfs don’t explode, so it is thought that mass accretion from a neighboring companion star plays a role in triggering the explosion. The accreted mass is the outer layer of the companion star, so it is normally composed mostly of hydrogen, but it was thought that it should also be possible for a white dwarf to accrete helium from a companion star which had lost its outer layer of hydrogen.
As the white dwarf strips matter from its companion star, not all of the material falls onto the white dwarf; some of it forms a cloud of circumstellar material around the binary star system. When a white dwarf explodes in a cloud of circumstellar material, it is expected that the shockwaves from the explosion traveling through the circumstellar material will excite atoms, causing them to emit strong radio waves. However, although many Type Ia supernovae have been observed exploding within a cloud of circumstellar material, so far astronomers had yet to observe radio wave emissions associated with a Type Ia supernova.
An international team of researchers, including members from Stockholm University and the National Astronomical Observatory of Japan, performed detailed observations of a Type Ia supernova which exploded in 2020. They revealed that this supernova was surrounded by circumstellar material consisting mainly of helium, and also succeeded in detecting radio waves from the supernova. Comparing the observed radio wave strength with theoretical models revealed that the progenitor white dwarf star had been accreting material at a rate of about 1/1000 the mass of the Sun every year. This is the first confirmed Type Ia supernova triggered by mass accretion from a companion star with an outer layer consisting primarily of helium.
It is expected that this observation of radio waves from a helium-rich Type Ia supernova will deepen our understanding of the explosion mechanism and the conditions before a Type Ia supernova. Now the team plans to search for radio emissions from other Type Ia supernovae to elucidate the evolution which leads to the explosion.
These results appeared as Kool et al. “A radio-detected Type Ia supernova with helium-rich circumstellar material” in the journal Nature on May 17, 2023.
END
First observed radio waves from a type Ia supernova
2023-05-18
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Hanging by a purple thread
2023-05-18
Kyoto, Japan -- Purple is a color that has historically been associated with nobility around the world. Japan is no exception. However, its distinct murasaki hue is threatened as the native gromwell plant -- synonymous with murasaki -- has become an endangered species.
Disease and cross-breeding with non-native species are partly to blame for murasaki's growing demise.
Now, a research group including Kyoto University, is leading a movement to raise awareness of gromwell's importance in preserving ...
Is vaping a new gateway into further substance use? New national study shows adolescent vapers much likelier to use cannabis and binge drink
2023-05-18
A new study of more than 50,000 US adolescents across the country indicates that vaping nicotine is strongly linked with an increased likelihood of high levels use of binge drinking and cannabis usage.
The findings, published today in the peer-reviewed journal Substance Use and Misuse, will add to growing public health concerns about the increased popularity of electronic cigarette (or ‘vaping’) use among young people.
“While the overall health risks of vaping are lower than smoking, electronic cigarettes are still harmful to adolescents and warrant ongoing ...
Researchers identify 10 pesticides toxic to neurons involved in Parkinson’s
2023-05-17
Researchers at UCLA Health and Harvard have identified 10 pesticides that significantly damaged neurons implicated in the development of Parkinson’s disease, providing new clues about environmental toxins’ role in the disease.
While environmental factors such as pesticide exposure have long been linked to Parkinson’s, it has been harder to pinpoint which pesticides may raise risk for the neurodegenerative disorder. Just in California, the nation’s largest agricultural producer and exporter, there are nearly 14,000 pesticide products with over 1,000 active ingredients registered for use.
Through a novel pairing ...
Hill Air Force Base and USU sign historic agreement
2023-05-17
A new agreement between Utah State University and Hill Air Force Base will create enhanced learning opportunities for students and spur innovative joint research efforts.
The Education Partnership Agreement was signed on May 11 by USU President Noelle Cockett and Wayne Ayer, a director of the Air Force Sustainment Center’s Engineering and Technical Management Directorate in Ogden.
“There are so many opportunities and technologies that exist within the Air Force that students and faculty can be a part of,” Ayer said. “By ...
SLU Institute for Healing Justice and Equity launches ‘Critical Futures’ podcast
2023-05-17
ST. LOUIS — The Institute for Healing Justice and Equity (IHJE) at Saint Louis University has launched "Critical Futures," a new podcast about imagining alternative futures.
The first episode "Reimagining Community Partnerships" explores anti-racist health policies and structural racism in the health care system and was produced with support from the Robert Wood Johnson Foundation (RWJF), as part of the work of the Anti-Racism Consortium.
“How do we dismantle these systems? What are we building in its wake to move forward so that we can stop having these conversations? Will that happen in our lifetime? ...
Uncovering universal physics in the dynamics of a quantum system
2023-05-17
New experiments using one-dimensional gases of ultra-cold atoms reveal a universality in how quantum systems composed of many particles change over time following a large influx of energy that throws the system out of equilibrium. A team of physicists at Penn State showed that these gases immediately respond, “evolving” with features that are common to all “many-body” quantum systems thrown out of equilibrium in this way. A paper describing the experiments appears May 17, 2023 in the journal Nature.
“Many major ...
NIR spectroscopy provides easy, cost-effective method for food allergen testing
2023-05-17
URBANA, Ill. – Food allergies pose a significant health risk, resulting in numerous hospitalizations every year, as even trace amounts of allergens can trigger severe reactions. Cross-contamination of food products can happen easily in the production process, so it’s important to have reliable methods of testing for allergens.
A new study conducted at the University of Illinois explores the application of near-infrared (NIR) spectroscopy to detect three types of allergens in quinoa flour. The researchers say the method ...
Cash or card? Consumers pay strategically to forget guilty purchases, study shows
2023-05-17
“Will you be paying with cash or card?”
It’s a question that’s been asked of consumers for decades. And despite the increasing popularity of digital payment methods, cash and card remain the most popular choices worldwide. In 2021, 65 percent of all point-of-sale transactions globally were made using cash or card, according to Fidelity National Information Services.
Past research shows that 90 percent of households use multiple payment methods, but new research from the University of Notre Dame takes a first look into how consumers choose between them. The study finds that ...
Impact Journals at SSP 45th Annual Meeting
2023-05-17
BUFFALO, NY-May 17, 2023 – Impact Journals will be participating as an exhibitor at the Society for Scholarly Publishing (SSP) 45th Annual Meeting, which convenes May 31–June 2, 2023, at the Oregon Convention Center & Hyatt Regency Portland in Portland, Oregon, USA. This year, the meeting theme is: “Transformation, Trust, and Transparency.”
“The pace of change in our industry continues unabated, with seismic shifts in areas such as the dissemination of research, business models, and the nature of the workplace. And yet, while pressure for change has become the new normal, ...
Can exercise lower the risk of developing Parkinson’s disease?
2023-05-17
MINNEAPOLIS – Getting regular exercise such as cycling, walking, gardening, cleaning and participating in sports may decrease the risk of developing Parkinson’s disease, according to new research published in the May 17, 2023, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study found female participants who exercised the most had a 25% lower rate of Parkinson’s disease when compared to those who exercised the least. The study does not prove that exercise lowers the risk of developing Parkinson’s disease. ...