Articles tagged with White Dwarfs
Astronomers have discovered the first close-up of a white dwarf star orbiting a companion star, set to explode into a supernova in a few million years. The white dwarf is unusual, with twice its expected mass and a diameter half that of Earth.
Researchers found that chaotic processes and asymmetry of explosions create diversity in brightness, with potential impact on precision distance measurements. Simulations suggest use of multi-dimensional models to refine distance estimates and improve expansion rate measurements.
Astronomers have discovered a rare type of stellar explosion known as SN 2008ha, which is 1000 times more powerful than a nova but 1000 times less powerful than a typical supernova. The explosion was detected by a 14-year-old student from New York and shed new light on the nature of stellar explosions.
Astronomers study SNR 0104, a Type Ia supernova remnant in the Small Magellanic Cloud, showing an unusual structure. The object's two bright lobes of emission suggest strong asymmetry in its formation.
Researchers will use chromospheres to measure star ages by studying sunspots and solar cycles. The team aims to extend the activity-age relation for solar-type stars up to the Milky Way's age, about 10 billion years.
Researchers are simulating Type Ia supernovas to better understand dark energy, a mysterious force causing the universe's expansion. The Blue Gene/P supercomputer will analyze how burning occurs in four possible scenarios leading to these exploding stars.
Researchers using Chandra X-ray Observatory data have reported a possible detection of a binary star system that was later destroyed in a supernova explosion. The new method provides great promise for finding the detailed origin of these cosmic events.
Researchers suggest that unusual supernovae could confirm the existence of intermediate-mass black holes in globular clusters. The proposed mechanism involves tidal disruption of a white dwarf star by a black hole, causing explosive burning and a unique signature.
The Keck Nuller has produced the first unified model for a nearby nova called RS Ophiuchi. The team observed the explosion using the nulling mode of the instrument and recorded the spectral signature of silicate dust at distances starting around 20 times the Earth-Sun distance, indicating that the dust pre-dates the explosion.
A team of astronomers discovered that a white dwarf, AE Aquarii, emits high-energy X-rays as it whirls around on its axis, similar to the Crab Nebula's pulsar. This behavior indicates that white dwarfs can accelerate charged particles to near-light speed, potentially contributing to cosmic rays.
Researchers have found eight white dwarf stars with pure carbon atmospheres, challenging existing theories on stellar evolution. The discovery may provide a unique view into the hearts of dying stars, shedding light on their evolutionary sequences.
Researchers from the Weizmann Institute of Science have observed a rare and detailed view of a Type Ia supernova event, revealing the remnants of a red giant star that fed a white dwarf. This unique observation supports a widely accepted model of these explosions.
Researchers discovered clear changes in interstellar material absorption, indicating the existence of gaseous shells around a white dwarf. The system was likely composed of a white dwarf feeding on its red giant companion, leading to the supernova explosion. This finding strongly supports the Type Ia supernova scenario.
The University of Chicago's Center for Astrophysical Thermonuclear Flashes will perform the world's most advanced simulations of exploding white dwarf stars using 2.5 million hours of processing time. The goal is to understand the nature of dark energy, a mysterious force dominating the universe.
Astronomers have discovered the faintest stars in a globular star cluster using Hubble's Advanced Camera for Surveys. The study reveals insights into the age, origin, and evolution of NGC 6397, which is estimated to be nearly 12 billion years old.
Researchers studied globular star cluster NGC 6397, capturing high-resolution images of faint stars. They identified two fundamental transitions in star physics related to age, which may refine the Milky Way's age. The findings provide insights into the physics of low mass stars and white dwarfs.
An international team of astronomers has identified the dimmest stars in globular star cluster NGC 6397 using NASA's Hubble Space Telescope. The discovery provides clues to the age of the Universe and the formation time of one of its earliest generations of stars.
Astronomers use Hubble Space Telescope to image two mysterious star types, including tiny, slow-burning stars and ancient, giant white dwarfs. The research pushes limits of observatory's capabilities, gathering data that will help refine theories about low-mass stars and the universe's age.
Astronomers discovered a brown dwarf in close orbit around a white dwarf, with a separation of less than 2/3 of the Sun's radius. The system formed after the red giant engulfed its companion and ejected its envelope, leaving behind a binary system.
Astronomers have observed a massive nuclear explosion on the surface of a white dwarf star, sending gas into space and creating a blast wave that accelerates electrons to nearly the speed of light. The European VLBI Network tracked the outburst using telescopes around the world, revealing a cigar-like shape in the blast wave.
Researchers monitored RS Oph's unprecedented detail using space- and ground-based telescopes, estimating gas expelled at 10 million km/h and a size larger than our solar system. The study sheds new light on super stellar explosions and helps predict the red giant's lifespan before becoming a white dwarf.
Researchers isolated Sirius B's light using Hubble Space Telescope, measuring its mass based on gravitational redshift. The result indicates Sirius B has a diameter less than Earth's but is denser and has a surface temperature of 25,000 degrees C.
Astronomer Nicolas Dauphas has refined the accuracy of the cosmic clock by comparing the decay of uranium-238 and thorium-232, estimating the age of the Milky Way at approximately 14.5 billion years, plus or minus 2 billion years.
Astronomers observed a binary star system called RX J0806.3+1527, where the white dwarf pair has an estimated mass of one-half the sun and orbits at a rate consistent with gravitational wave predictions. The system is believed to be among the brightest sources of gravitational waves in the galaxy.
The Chandra X-ray Observatory has observed an X-ray outburst from the highly evolved red giant star Mira A, revealing a bridge of hot matter streaming between it and its companion white dwarf. The detection provides insights into interactions between binary systems, including those with a collapsed star.
Researchers have discovered two candidate planets orbiting white dwarfs, which are the remnants of dead stars. The team used a combination of telescopes to detect these planets, which could provide clues about the solar system's formation and the presence of life in the galaxy.
A new discovery by Pilar Ruiz-Lapuente and colleagues identifies a clear path for Type Ia supernovae to form in binary star systems. The research found that the companion star is similar to our sun, but slightly older and with high heavy-element content, supporting the theory that Type Ia supernovae originate from these systems.
Researchers found stable ring-shaped magnetic field configurations in magnetic A-stars, White Dwarf stars, and neutron stars, supporting the 'fossil field' hypothesis. These fields can persist for hundreds of millions of years, surviving the star's life span.
Researchers using European Southern Observatory's Very Large Telescope discovered a unique type Ia supernova that exploded within a flat, dense disk of dust and gas. The findings suggest that this and other precursors resemble protoplanetary nebulae, which may indicate wide differences among their progenitors.
Researchers observed mass-losing stars in cataclysmic variables and found most secondary stars lack carbon and other elements. The unusual abundance patterns suggest stellar material formed through CNO burning, a process thought to occur in high-mass stars.
Astronomers have identified a new type of star in a compact binary system, exhibiting properties similar to brown dwarf stars. The discovery sheds light on the formation and evolution of extra-solar planets, which are often found close to their host stars.
The Sloan Digital Sky Survey has identified dozens of dim binary star systems throughout the Milky Way, which are older and cooler than previously thought. The study finds that these close-binary systems have a low rate of mass transfer from the red dwarf to the white dwarf, making them less likely targets for many telescopes.
Researchers John Debes and Steinn Sigurdsson predict unstable planets will collide, creating 'reborn' planets around white dwarfs. This process could create heavy bombardment of material into inner planetary systems, explaining phenomena like dusty white dwarfs and metal-polluted atmospheres.
New Hubble images show gas shells produced by novae that may revolutionize our understanding of galactic evolution. The findings imply that novae play a significant role in the distribution of heavier elements and planetary system development, contradicting previous predictions.
Researchers from UD and Denmark confirmed Subramanyan Chandresekhar's theory on the structure of compact stars, including pulsars, black holes, and white dwarf stars. By analyzing distances to a dozen white dwarf stars using HIPPARCOS data, they verified the theory, which predicts the size of white dwarf stars based on their mass.
Astronomers have discovered a 45-day cycle of radiation surges from V1159 Ori, a cataclysmic variable system. The energy release is due to hydrogen buildup around the white dwarf triggering a massive dump of material, resulting in an enormous energy surge.