Articles tagged with White Dwarfs
Novae are sudden, short-lived brightenings of stars caused by thermonuclear explosions on white dwarf surfaces. NASA's Fermi Gamma-ray Space Telescope has detected gamma-rays from these events, showing they release up to 100,000 times the annual energy output of the sun.
Researchers used the Fermi Gamma-ray Space Telescope to discover high-energy gamma rays emitted by an exploding star. The surprising finding dispels the notion that classical nova explosions lack the power to produce such radiation.
Astronomers confirm first self-lensing binary star system, where the closer star's mass is measured by its magnifying effect on light from its companion. This discovery improves research on white dwarfs and galaxy age, using gravitational lensing to reveal new insights into these celestial objects.
Researchers have discovered that many hot white dwarfs' atmospheres are contaminated by rocky material from planetary systems, suggesting a similar proportion of stars build terrestrial planets. This breakthrough has implications for the ultimate fate of the Earth billions of years in the future.
A new analysis of normal Type Ia supernovae reveals a range of masses, most near or below the Chandrasekhar limit. The SNfactory team used spectrography to 'weigh' the leftover debris, comparing masses and factors with light curves.
Astronomers have found a rare stellar system featuring a neutron star, two white dwarf stars, in an incredibly close orbit. By measuring the gravitational perturbations in this system, scientists can gain insights into the nature of gravity and potentially detect problems with General Relativity.
Astronomers have discovered a 3-star system that challenges the strong equivalence principle in Albert Einstein's theory of General Relativity. The system, consisting of two white dwarf stars and a superdense pulsar, allows for precise timing observations to test the theory's validity.
Astronomers found a water-rich asteroid orbiting an exhausted star, indicating the presence of Earth-like exoplanets. The discovery suggests that the star GD 61 had the potential to contain habitable planets, with water and rocky surfaces being key ingredients.
Researchers have found evidence of a water-rich rocky planetary body in the shattered remains of a planet that once orbited a white dwarf star. The discovery marks the first time water has been pinpointed in a rocky body outside our solar system, providing insights into the formation and evolution of habitable planets.
Researchers used the Hubble Space Telescope to measure alpha, the fine-structure constant, on a white dwarf star. They found no significant variation in alpha near the star and compared it with laboratory measurements.
A team of researchers used radio telescopes to precisely locate SS Cygni at 370 light-years from Earth, resolving a major problem in understanding the star's regular outbursts. The new distance measurement brings the system into line with standard explanations for similar systems.
A team of astronomers has solved a decade-old puzzle by accurately measuring the distance to star system SS Cygni at 372 light years. The team used radio telescopes and coordinated with amateur astronomers to pinpoint the exact location of the system, confirming their understanding of exotic objects like black holes.
The Ring Nebula's true shape has been revealed by NASA's Hubble Space Telescope, showing a more complex structure than previously thought. The new observations have allowed researchers to construct the most precise 3-D model of the nebula, revealing details such as a blue, football-shaped structure and dark, irregular knots of dense gas.
Researchers have found evidence of building blocks for Earth-sized planets in the atmospheres of two burned-out stars called white dwarfs. The silicon and low levels of carbon in these dead stars suggest that asteroid-like debris is falling onto them, potentially creating rocky planet assembly around stars.
Astronomers have found signs of rocky material in the atmospheres of two dead stars, suggesting that terrestrial planets may still exist. The debris detected around these white dwarfs is thought to be the remains of asteroids that were shredded by the star's gravity.
Researchers have confirmed Einstein's theory of general relativity by observing a unique binary star system with a massive neutron star and a white dwarf. The study found that the system's gravitational waves match exactly what Einstein's theory predicts, providing strong evidence for the validity of the theory.
Researchers propose that white dwarf stars can support habitable planets, allowing for detection of biomarkers like oxygen and methane. The James Webb Space Telescope will be capable of detecting these signs after only a few hours of observation time.
Astronomers analyzed X-ray observations from the Suzaku satellite to understand the composition of Kepler's supernova, finding it held roughly three times the amount of metals as the sun. This discovery will aid in fine-tuning knowledge of the universe beyond our galaxy.
Astronomers have found the farthest Type Ia supernova, named SN Wilson, with a distance of over 13.8 billion years ago. This discovery provides insights into how these stars explode and test theories about dark energy.
Astronomers detect two Type 1a supernovae, designated Supernova 2013X and Supernova 2012ha, which provide valuable information for measuring cosmic distances. The explosions occurred hundreds of millions of years ago and have traveled to Earth, offering insights into the expansion of the universe.
A new study suggests that future evidence for extraterrestrial life might come from dying stars, specifically from planets orbiting white dwarfs. Detectable oxygen in the atmosphere of these planets could indicate the presence of life, and a recent simulation indicates JWST can detect this with only a few hours of observation time.
New research suggests that planets orbiting white or brown dwarfs are unlikely to support life due to the cooling and shrinking of their habitable zones. The study's findings indicate that such planets would have had to undergo a 'sterilization phase' in the past, making them dead for hosting life.
Researchers use Multi-Object Double Spectrograph to determine composition of Type Ia supernovae, finding them likely caused by interaction between two white dwarfs. This discovery sheds light on the expansion and acceleration of the universe, opening new ideas in understanding.
A type of exploding star that fails to detonate, known as a failed explosion, is probably the cause of most peculiar supernovae. These dim stars are anywhere from 10-100 times fainter than normal ones and may account for approximately 15% of all type Ia supernovae.
A team of astronomers has detected gravitational waves at optical wavelengths in light from a pair of eclipsing white dwarf stars. The effect, predicted by Einstein's theory of general relativity, causes the stars to inch closer together and orbit each other faster.
A team of astronomers has discovered that at least some thermonuclear (Type Ia) supernovae originate from recurrent novae, contradicting previous theories. The study, led by Ben Dilday, reveals multiple ways to make a Type Ia supernova and has implications for understanding the differences seen in these 'standard candles'.
Researchers have discovered a binary star system, QU Carinae, which may produce a type Ia supernova. The system's white dwarf is accumulating mass from a giant star, producing sodium gas that could be detected after the explosion.
A team of astronomers studied 23 Type Ia supernovae to find signatures of gas around the explosions. They found that more powerful explosions came from systems with outflows of gas, but only a fraction showed evidence for these outflows.
Researchers found four white dwarfs with dust from shattered planetary bodies containing oxygen, magnesium, iron, and silicon, similar to the Earth's composition. The study provides evidence of a 'terminal phase' in the death of rocky exoplanets, potentially shedding light on their destruction process.
Astronomers have identified two 11- to 12-billion-year-old white dwarf stars, the oldest and closest known to Earth. Located 100 light years away, these stars are believed to be among the first formed in the Universe soon after the Big Bang.
Studies using X-ray and ultraviolet observations from NASA's Swift satellite provide new insights into the elusive origins of Type Ia supernovae. The research suggests that the companion to a white dwarf is either a smaller, younger star similar to our sun or another white dwarf.
A research team at the University of Pittsburgh used the Sloan Digital Sky Survey to determine that the merger of double white dwarfs is a plausible explanation for Type Ia supernovae. The study found that one double white dwarf merger event occurs in the Milky Way about once a century, remarkably close to the rate of observed Type Ia ...
Researchers have confirmed that Type Ia supernovae are produced by the explosion of carbon-oxygen white dwarf stars. By analyzing a fluke observation of SN2011fe four hours after its explosion, scientists set stricter limits on the size of the progenitor star, ruling out other possibilities.
Astronomers have solved a longstanding mystery on the type of star that caused a Type Ia supernova seen in a nearby galaxy. The Hubble Space Telescope detected faint white dwarf remnants, contradicting previous theories and suggesting two tightly orbiting stars may have collided to trigger the explosion.
A team led by LSU Professor Bradley Schaefer and graduate student Ashley Pagnotta discovered the origin of thermonuclear supernovae as a pair of white dwarf stars. The study resolves the decades-long 'progenitor problem' in astrophysics, with no remaining possible explanations for the explosions.
The study of the closest supernova in 25 years has shed new light on its formation. The team found that the exploding star was a white dwarf, and while they couldn't rule out a white dwarf merger, their results suggest a medium-sized star supplied the white dwarf with extra material to trigger the explosion.
An international team of scientists has discovered that a recently exploded supernova was a 'white dwarf' star, challenging the long-held theory that it was a red giant. The finding provides direct evidence that white dwarfs are responsible for Type Ia supernovae.
A team of scientists has observed the early stages of a Type Ia supernova, refining our understanding of these explosive events. The discovery suggests that the primary star was a carbon-oxygen white dwarf, and analysis of matter ejected by the explosion points to a possible subgiant or main-sequence star as the secondary companion.
Astronomers have observed the closest Type Ia supernova in decades, providing direct evidence for what a carbon-oxygen white dwarf looks like before it explodes. The study reveals that the supernova's progenitor was likely a binary system with a small white-dwarf star orbiting a companion.
Researchers used Hubble Space Telescope data to rule out some proposed progenitor systems for Type Ia supernovae. The study suggests that the companion star was likely a normal star like our sun, a subgiant, or possibly a white dwarf.
Astronomers have determined how a Type Ia supernova occurs, involving a dense white dwarf and main-sequence star. The study provides new insights into the universe's expansion and cosmic origins.
Astronomers discover how blue stragglers, old stars appearing younger than expected, are created through mass transfer. The study reveals that these stars eat up the mass of their giant-star companion, allowing them to continue burning and living longer.
A new survey suggests that many Type Ia supernovae result from the merger of two white dwarf stars, challenging previous theories about their origins. The study, which analyzed data from distant exploding stars, found that these events may be more common than previously thought and could provide insights into the history of the universe.
Astronomers propose a new way to search for supernova precursors by studying the spin of white dwarfs. This process could lead to a time delay of up to a billion years before the explosion, allowing for detection by upcoming surveys.
Researchers found evidence of gas outflows from the supernova ancestors, suggesting they don't originate from white dwarfs. This discovery is crucial for understanding Type Ia supernovae and their immense luminosity.
Scientists have discovered a pair of white dwarfs that are spiraling into each other at breakneck speeds, allowing them to test Einstein's theory of general relativity. The merger could also shed light on the origin of underluminous supernovae.
Astronomers have discovered a binary system consisting of two white dwarfs orbiting each other every 39 minutes. The stars are expected to collide and merge in 37 million years, resulting in the formation of a single star. This discovery marks the first time such an event has been observed.
A new paper suggests that potentially habitable planets orbiting white dwarfs could be much easier to find than other exoplanets. The study proposes a survey of the 20,000 closest white dwarfs, which could be detected using a 1-meter ground telescope.
Researchers have found a dozen double-star systems consisting of two white dwarfs, with half expected to merge and explode as supernovae. The merged stars will stir space-time, creating gravitational waves and causing them to spiral closer together.
Astronomers have discovered a neutron star with twice the mass of our Sun, ruling out certain theoretical models for its internal composition. The discovery has significant implications for astrophysics, nuclear physics, and our understanding of matter at extreme densities.
Astronomers have detected gamma rays from a nova, dispelling the idea that these explosions are not powerful enough to produce high-energy radiation. The newly detected explosion is equivalent to about 1,000 times the energy of the sun.
Astronomers detected gamma rays from a nova using NASA's Fermi Gamma-ray Space Telescope, surprising scientists with evidence of high-energy radiation. The discovery sheds new light on the power of nova explosions and their potential to emit gamma rays.
Scientists investigate white dwarf remnants and binary systems to understand supernovae origins. However, the search for accreting white dwarfs yields few results, leading researchers to reconsider their theories.
Astronomers have identified a possible new class of supernovae that produces high levels of calcium, which could explain the element's abundance in galaxies and life on Earth. The 'calcium-rich' supernovae were discovered by detecting unusual elements in their spectra.
A team of UCSB astrophysicists has discovered a unique eclipsing binary star system, confirming a theory about white dwarf stars. The researchers measured the size of a rare helium-core white dwarf for the first time, revealing it burns hotter and is larger than ordinary white dwarfs.
The HM Cancri binary system consists of two white dwarfs with an orbital period of 5.4 minutes, making it the smallest and closest to Earth. Mass is flowing from one star to another, and this system has the potential to emit gravitational waves.
Researchers have found two Earth-sized bodies with oxygen-rich atmospheres, which are not planets but rather unusual white dwarf stars. The discovery was made using data from the Sloan Digital Sky Survey and suggests that these stars may have descended from massive progenitor stars.
Astronomers have discovered a possible new type of supernova that occurs when helium flows onto a white dwarf, causing a thermonuclear explosion. The object, dubbed SN 2002bj, is characterized by its rapid rise and fall and strong helium signature.
A new class of supernova was discovered, predicted by UC Santa Barbara scientists Lars Bildsten and colleagues. The event is fainter than typical supernovae and rises and falls in brightness over a few weeks.
A team of researchers has created the first full-star simulation of a white dwarf star's final hours leading up to a Type Ia supernova explosion. The simulations, run on supercomputers, provide detailed insights into the process and may be critical in understanding how these massive stellar explosions occur.