Latest news with #whiteDwarf
Yahoo
04-07-2025
- Science
- Yahoo
First-ever evidence of star 'double detonation' captured in stunning image
When you buy through links on our articles, Future and its syndication partners may earn a commission. For the first time, astronomers have captured stunning visual evidence of a star double-detonating itself to death. The twin eruption was discovered by scientists studying two concentric rings of calcium that surround SNR 0509-67.5, a remnant of a star that met its explosive demise in a type Ia supernova centuries ago. And the discovery isn't just a pretty picture. The researchers who made it say that much of our knowledge of how the universe expands — a major controversy in cosmology — depends on reliably measuring this type of supernova, which is also the primary source of iron throughout the cosmos. The scientists published their findings July 2 in the journal Nature Astronomy. For these reasons, "the explosions of white dwarfs play a crucial role in astronomy," study first author Priyam Das, a graduate student at the University of New South Wales Canberra in Australia, said in a statement. "Yet, despite their importance, the long-standing puzzle of the exact mechanism triggering their explosion remains unsolved." Type Ia supernovas occur when the material from one star is stolen by the husk of a co-orbiting dead star, known as a white dwarf, leading to a gigantic thermonuclear explosion. Yet not all the ways that white dwarves detonate are accounted for. Astronomers assume that these white dwarves steadily snatch their neighboring star's material, accumulating it until they reach a critical mass — the Chandrasekhar limit — and explode. But astronomers have found hints suggesting that this isn't the only way the husks blow up. Related: Supernova that lit up Earth's skies 843 years ago has a flowering 'zombie star' at its heart — and it's still exploding To search for direct evidence of a different ype of detonation, the researchers pointed the European Southern Observatory's Very Large Telescope at SNR 0509-67.5, a supernova that displays a clear shock wave shell pattern. Using the telescope's Multi Unit Spectroscopic Explorer instrument, they found two separate rings of calcium surrounding the remnants of the explosion. This is "a clear indication that white dwarfs can explode well before they reach the famous Chandrasekhar mass limit, and that the 'double-detonation' mechanism does indeed occur in nature," second-author Ivo Seitenzahl, a nuclear astrophysicist at the University of New South Wales Canberra, said in the statement. RELATED STORIES —Rare quadruple supernova on our 'cosmic doorstep' will shine brighter than the moon when it blows up in 23 billion years —Weird repeating explosion beyond the Milky Way is one of the hottest blasts scientists have ever seen —A nearby supernova nearly blew our solar system to bits 4 billion years ago, new research suggests The researchers propose that this white dwarf exploded by blanketing itself in stolen helium from its neighbor that then ignited, sending a shockwave inwards that caused the dead star's core to blow in a second, larger, explosion. Studying this dual detonation could have important implications for our wider understanding of the universe. No matter which way they occur, type Ia supernovas are thought to always explode with the same brightness, making them "standard candles" from which astronomers can measure far-off distances and calculate the expansion rate of our universe. In recent years, contesting measurements of this expansion rate, known as the Hubble constant, have sparked a major crisis in cosmology. "This tangible evidence of a double-detonation not only contributes towards solving a long-standing mystery, but also offers a visual spectacle," Das said. "Revealing the inner workings of such a spectacular cosmic explosion is incredibly rewarding."
Globe and Mail
03-07-2025
- Science
- Globe and Mail
Astronomers get picture of aftermath of a star's double detonation for the first time
The explosion of a star, called a supernova, is an immensely violent event. It usually involves a star more than eight times the mass of our sun that exhausts its nuclear fuel and undergoes a core collapse, triggering a single powerful explosion. But a rarer kind of supernova involves a different type of star - a stellar ember called a white dwarf - and a double detonation. Researchers have obtained photographic evidence of this type of supernova for the first time, using the European Southern Observatory's Chile-based Very Large Telescope. The back-to-back explosions obliterated a white dwarf that had a mass roughly equal to the sun and was located about 160,000 light-years from Earth in the direction of the constellation Dorado in a galaxy near the Milky Way called the Large Magellanic Cloud. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The image shows the scene of the explosion roughly 300 years after it occurred, with two concentric shells of the element calcium moving outward. This type of explosion, called a Type Ia supernova, would have involved the interaction between a white dwarf and a closely orbiting companion star - either another white dwarf or an unusual star rich in helium - in what is called a binary system. The primary white dwarf through its gravitational pull would begin to siphon helium from its companion. The helium on the white dwarf's surface at some point would become so hot and dense that it would detonate, producing a shockwave that would compress and ignite the star's underlying core and trigger a second detonation. First images shared from the Vera C. Rubin Observatory reveal why it will change astronomy forever 'Nothing remains. The white dwarf is completely disrupted,' said Priyam Das, a doctoral student in astrophysics at the University of New South Wales Canberra in Australia, lead author of the study published on Wednesday in the journal Nature Astronomy. 'The time delay between the two detonations is essentially set by the time it takes the helium detonation to travel from one pole of the star all the way around to the other. It's only about two seconds,' said astrophysicist and study co-author Ivo Seitenzahl, a visiting scientist at the Australian National University in Canberra. In the more common type of supernova, a remnant of the massive exploded star is left behind in the form of a dense neutron star or a black hole. The researchers used the Very Large Telescope's Multi-Unit Spectroscopic Explorer, or MUSE, instrument to map the distribution of different chemical elements in the supernova aftermath. Calcium is seen in blue in the image - an outer ring caused by the first detonation and an inner ring by the second. These two calcium shells represent 'the perfect smoking-gun evidence of the double-detonation mechanism,' Das said. 'We can call this forensic astronomy - my made-up term - since we are studying the dead remains of stars to understand what caused the death,' Das said. Can science solve the puzzle of consciousness? Stars with up to eight times the mass of our sun appear destined to become a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a 'red giant' stage, eventually leaving behind a compact core - the white dwarf. The vast majority of these do not explode as supernovas. While scientists knew of the existence of Type Ia supernovas, there had been no clear visual evidence of such a double detonation until now. Type Ia supernovas are important in terms of celestial chemistry in that they forge heavier elements such as calcium, sulfur and iron. 'This is essential for understanding galactic chemical evolution including the building blocks of planets and life,' Das said. A shell of sulfur also was seen in the new observations of the supernova aftermath. Iron is a crucial part of Earth's planetary composition and, of course, a component of human red blood cells. In addition to its scientific importance, the image offers aesthetic value. 'It's beautiful,' Seitenzahl said. 'We are seeing the birth process of elements in the death of a star. The Big Bang only made hydrogen and helium and lithium. Here we see how calcium, sulfur or iron are made and dispersed back into the host galaxy, a cosmic cycle of matter.'
Reuters
03-07-2025
- Science
- Reuters
Astronomers get picture of aftermath of a star's double detonation
WASHINGTON, July 2 (Reuters) - The explosion of a star, called a supernova, is an immensely violent event. It usually involves a star more than eight times the mass of our sun that exhausts its nuclear fuel and undergoes a core collapse, triggering a single powerful explosion. But a rarer kind of supernova involves a different type of star - a stellar ember called a white dwarf - and a double detonation. Researchers have obtained photographic evidence of this type of supernova for the first time, using the European Southern Observatory's Chile-based Very Large Telescope. The back-to-back explosions obliterated a white dwarf that had a mass roughly equal to the sun and was located about 160,000 light‑years from Earth in the direction of the constellation Dorado in a galaxy near the Milky Way called the Large Magellanic Cloud. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The image shows the scene of the explosion roughly 300 years after it occurred, with two concentric shells of the element calcium moving outward. This type of explosion, called a Type Ia supernova, would have involved the interaction between a white dwarf and a closely orbiting companion star - either another white dwarf or an unusual star rich in helium - in what is called a binary system. The primary white dwarf through its gravitational pull would begin to siphon helium from its companion. The helium on the white dwarf's surface at some point would become so hot and dense that it would detonate, producing a shockwave that would compress and ignite the star's underlying core and trigger a second detonation. "Nothing remains. The white dwarf is completely disrupted," said Priyam Das, a doctoral student in astrophysics at the University of New South Wales Canberra in Australia, lead author of the study published on Wednesday in the journal Nature Astronomy, opens new tab. "The time delay between the two detonations is essentially set by the time it takes the helium detonation to travel from one pole of the star all the way around to the other. It's only about two seconds," said astrophysicist and study co-author Ivo Seitenzahl, a visiting scientist at the Australian National University in Canberra. In the more common type of supernova, a remnant of the massive exploded star is left behind in the form of a dense neutron star or a black hole. The researchers used the Very Large Telescope's Multi-Unit Spectroscopic Explorer, or MUSE, instrument to map the distribution of different chemical elements in the supernova aftermath. Calcium is seen in blue in the image - an outer ring caused by the first detonation and an inner ring by the second. These two calcium shells represent "the perfect smoking-gun evidence of the double-detonation mechanism," Das said. "We can call this forensic astronomy - my made-up term - since we are studying the dead remains of stars to understand what caused the death," Das said. Stars with up to eight times the mass of our sun appear destined to become a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core - the white dwarf. The vast majority of these do not explode as supernovas. While scientists knew of the existence of Type Ia supernovas, there had been no clear visual evidence of such a double detonation until now. Type Ia supernovas are important in terms of celestial chemistry in that they forge heavier elements such as calcium, sulfur and iron. "This is essential for understanding galactic chemical evolution including the building blocks of planets and life," Das said. A shell of sulfur also was seen in the new observations of the supernova aftermath. Iron is a crucial part of Earth's planetary composition and, of course, a component of human red blood cells. In addition to its scientific importance, the image offers aesthetic value. "It's beautiful," Seitenzahl said. "We are seeing the birth process of elements in the death of a star. The Big Bang only made hydrogen and helium and lithium. Here we see how calcium, sulfur or iron are made and dispersed back into the host galaxy, a cosmic cycle of matter."
Yahoo
02-07-2025
- Science
- Yahoo
Astronomers get picture of aftermath of a star's double detonation
By Will Dunham WASHINGTON (Reuters) -The explosion of a star, called a supernova, is an immensely violent event. It usually involves a star more than eight times the mass of our sun that exhausts its nuclear fuel and undergoes a core collapse, triggering a single powerful explosion. But a rarer kind of supernova involves a different type of star - a stellar ember called a white dwarf - and a double detonation. Researchers have obtained photographic evidence of this type of supernova for the first time, using the European Southern Observatory's Chile-based Very Large Telescope. The back-to-back explosions obliterated a white dwarf that had a mass roughly equal to the sun and was located about 160,000 light‑years from Earth in the direction of the constellation Dorado in a galaxy near the Milky Way called the Large Magellanic Cloud. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The image shows the scene of the explosion roughly 300 years after it occurred, with two concentric shells of the element calcium moving outward. This type of explosion, called a Type Ia supernova, would have involved the interaction between a white dwarf and a closely orbiting companion star - either another white dwarf or an unusual star rich in helium - in what is called a binary system. The primary white dwarf through its gravitational pull would begin to siphon helium from its companion. The helium on the white dwarf's surface at some point would become so hot and dense that it would detonate, producing a shockwave that would compress and ignite the star's underlying core and trigger a second detonation. "Nothing remains. The white dwarf is completely disrupted," said Priyam Das, a doctoral student in astrophysics at the University of New South Wales Canberra in Australia, lead author of the study published on Wednesday in the journal Nature Astronomy. "The time delay between the two detonations is essentially set by the time it takes the helium detonation to travel from one pole of the star all the way around to the other. It's only about two seconds," said astrophysicist and study co-author Ivo Seitenzahl, a visiting scientist at the Australian National University in Canberra. In the more common type of supernova, a remnant of the massive exploded star is left behind in the form of a dense neutron star or a black hole. The researchers used the Very Large Telescope's Multi-Unit Spectroscopic Explorer, or MUSE, instrument to map the distribution of different chemical elements in the supernova aftermath. Calcium is seen in blue in the image - an outer ring caused by the first detonation and an inner ring by the second. These two calcium shells represent "the perfect smoking-gun evidence of the double-detonation mechanism," Das said. "We can call this forensic astronomy - my made-up term - since we are studying the dead remains of stars to understand what caused the death," Das said. Stars with up to eight times the mass of our sun appear destined to become a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core - the white dwarf. The vast majority of these do not explode as supernovas. While scientists knew of the existence of Type Ia supernovas, there had been no clear visual evidence of such a double detonation until now. Type Ia supernovas are important in terms of celestial chemistry in that they forge heavier elements such as calcium, sulfur and iron. "This is essential for understanding galactic chemical evolution including the building blocks of planets and life," Das said. A shell of sulfur also was seen in the new observations of the supernova aftermath. Iron is a crucial part of Earth's planetary composition and, of course, a component of human red blood cells. In addition to its scientific importance, the image offers aesthetic value. "It's beautiful," Seitenzahl said. "We are seeing the birth process of elements in the death of a star. The Big Bang only made hydrogen and helium and lithium. Here we see how calcium, sulfur or iron are made and dispersed back into the host galaxy, a cosmic cycle of matter."
CNA
02-07-2025
- Science
- CNA
Astronomers get picture of aftermath of a star's double detonation
WASHINGTON :The explosion of a star, called a supernova, is an immensely violent event. It usually involves a star more than eight times the mass of our sun that exhausts its nuclear fuel and undergoes a core collapse, triggering a single powerful explosion. But a rarer kind of supernova involves a different type of star - a stellar ember called a white dwarf - and a double detonation. Researchers have obtained photographic evidence of this type of supernova for the first time, using the European Southern Observatory's Chile-based Very Large Telescope. The back-to-back explosions obliterated a white dwarf that had a mass roughly equal to the sun and was located about 160,000 light‑years from Earth in the direction of the constellation Dorado in a galaxy near the Milky Way called the Large Magellanic Cloud. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The image shows the scene of the explosion roughly 300 years after it occurred, with two concentric shells of the element calcium moving outward. This type of explosion, called a Type Ia supernova, would have involved the interaction between a white dwarf and a closely orbiting companion star - either another white dwarf or an unusual star rich in helium - in what is called a binary system. The primary white dwarf through its gravitational pull would begin to siphon helium from its companion. The helium on the white dwarf's surface at some point would become so hot and dense that it would detonate, producing a shockwave that would compress and ignite the star's underlying core and trigger a second detonation. "Nothing remains. The white dwarf is completely disrupted," said Priyam Das, a doctoral student in astrophysics at the University of New South Wales Canberra in Australia, lead author of the study published on Wednesday in the journal Nature Astronomy. "The time delay between the two detonations is essentially set by the time it takes the helium detonation to travel from one pole of the star all the way around to the other. It's only about two seconds," said astrophysicist and study co-author Ivo Seitenzahl, a visiting scientist at the Australian National University in Canberra. In the more common type of supernova, a remnant of the massive exploded star is left behind in the form of a dense neutron star or a black hole. The researchers used the Very Large Telescope's Multi-Unit Spectroscopic Explorer, or MUSE, instrument to map the distribution of different chemical elements in the supernova aftermath. Calcium is seen in blue in the image - an outer ring caused by the first detonation and an inner ring by the second. These two calcium shells represent "the perfect smoking-gun evidence of the double-detonation mechanism," Das said. "We can call this forensic astronomy - my made-up term - since we are studying the dead remains of stars to understand what caused the death," Das said. Stars with up to eight times the mass of our sun appear destined to become a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core - the white dwarf. The vast majority of these do not explode as supernovas. While scientists knew of the existence of Type Ia supernovas, there had been no clear visual evidence of such a double detonation until now. Type Ia supernovas are important in terms of celestial chemistry in that they forge heavier elements such as calcium, sulfur and iron. "This is essential for understanding galactic chemical evolution including the building blocks of planets and life," Das said. A shell of sulfur also was seen in the new observations of the supernova aftermath. Iron is a crucial part of Earth's planetary composition and, of course, a component of human red blood cells. In addition to its scientific importance, the image offers aesthetic value. "It's beautiful," Seitenzahl said. "We are seeing the birth process of elements in the death of a star. The Big Bang only made hydrogen and helium and lithium. Here we see how calcium, sulfur or iron are made and dispersed back into the host galaxy, a cosmic cycle of matter."
