Tag

Stellar Mergers

All articles tagged with #stellar mergers

science1 month ago

Record-Breaking Seven-Hour Gamma-Ray Burst Points to Rare Stellar Merger

Astronomers have identified GRB 250702B, a gamma-ray burst lasting approximately 25,000 seconds, which shatters previous duration records. This seven-hour signal is believed to result from a rare helium merger event, where a stellar-mass black hole consumed a stripped helium star from the inside. While traditional bursts stem from collapsing stars or neutron star mergers, this extended duration suggests a distinct astrophysical process. Detecting such long, dim signals remains challenging for current telescopes, but the upcoming COSI telescope, scheduled for launch in 2027, aims to improve detection capabilities for these rare events.

via BBC Sky at Night Magazine|

#astronomy #black-holes #gamma-ray-bursts

science5 months ago•5 min saved

Cosmic Recycling: Heavier Black Holes Form From Repeated Mergers

An analysis of 153 black-hole mergers via gravitational waves reveals two populations: lighter black holes up to ~40 solar masses with spins aligned from stellar collapse, and heavier black holes above ~45 solar masses with chaotic spins, indicating they are second-generation products from prior mergers. This provides evidence that the heaviest black holes are created by repeated collisions in dense stellar environments rather than direct collapse from single stars.

via WIRED|

#astronomy #black-holes #gravitational-waves

science1 year ago•5 min saved

Advancements in Gravitational Wave Research Uncover Record Black Hole Collisions

Using gravitational wave detectors LIGO, Virgo, and KAGRA, scientists have identified a 'stellar graveyard' filled with mergers of black holes and neutron stars, including the heaviest black holes observed to date, which enhances understanding of stellar evolution and the universe's expansion rate. The data also tests Einstein's theory of gravity and improves measurement of the Hubble Constant.

via Space|

#black-holes #gravitational-waves #neutron-stars

science1 year ago•4 min saved

Mystery of Hypervelocity White Dwarfs Solved

Astronomers have proposed a new model explaining hypervelocity white dwarfs as remnants of violent stellar mergers and faint supernovae, which can propel these dense stars out of the Milky Way at extreme speeds, resolving previous mysteries about their origins and characteristics.

via Space|

#galactic-ejection #hypervelocity #science

science1 year ago•7 min saved

Astronomers Discover White Dwarf Resulting From Stellar Collision

Researchers using Hubble's UV data discovered that the high-mass white dwarf WD 0525+526 is likely the remnant of a stellar merger, evidenced by faint carbon signatures on its surface. This finding provides rare direct evidence of white dwarf mergers, which are important for understanding stellar evolution and supernovae, and highlights the importance of ultraviolet observations in detecting such phenomena.

via Universe Today|

#carbon-signatures #science #stellar-mergers

science1 year ago•5 min saved

Unraveling the Cosmic Mystery: Magnetars and Plasma Bubbles Behind Fast Radio Bursts

Researchers have linked fast radio bursts (FRBs) to magnetars, highly magnetized neutron stars, which are more frequently found in massive, metal-rich galaxies. This suggests that these galaxies provide the ideal conditions for magnetar formation, often resulting from the merger of massive stars. The study, utilizing the Deep Synoptic Array-110, has localized 70 FRBs, offering insights into the environments conducive to FRB occurrences and magnetar formation.

via SciTechDaily|

#astronomy #fast-radio-bursts #galaxies

science1 year ago•2 min saved

Astronomers Link Fast Radio Bursts to Massive Star-Forming Galaxies

Astronomers have linked fast radio bursts (FRBs) to massive, star-forming galaxies, suggesting they originate from magnetars—highly magnetic neutron stars formed from stellar mergers. This discovery, led by Kritti Sharma at Caltech, indicates that metal-rich environments in these galaxies may facilitate the formation of magnetars, which are potential sources of FRBs. The study, published in Nature, also explores the possibility that magnetars result from the fusion of two stars, offering insights into their formation and the enigmatic nature of FRBs.

via Livescience.com|

#astronomy #fast-radio-bursts #galaxies

astronomy2 years ago•3 min saved

"Unraveling the Magnetic Mystery of the Enigmatic 'Dragon's Egg' Star"

Astronomers have solved the mystery of the enigmatic 'Dragon's Egg' star system, finding that two of the original three stars merged violently, creating the unique nebula and two mismatched stars. The larger star's unexpected magnetic field led researchers to analyze the system, revealing the stars' different ages and unusual chemical composition. This evidence supports the theory that stellar mergers produce magnetic fields around massive stars, shedding light on the cosmic rarity of such phenomena.

via ScienceAlert|

#astronomy #cosmic-mystery #dragons-egg-nebula

astronomy3 years ago•2 min saved

JWST's Potential Answers to the Mysterious Disappearance of a Massive Star

Astronomers have observed a massive star, N6946-BH1, that disappeared in 2009 and is now considered a failed supernova. Using data from the James Webb Space Telescope (JWST), they have discovered a bright infrared source that could be a remnant dust shell or material infalling into a black hole. Surprisingly, they found three sources instead of one, suggesting a stellar merger rather than a failed supernova. This challenges our understanding of supernovae and stellar mass black holes, and further observations will help distinguish between stellar mergers and true failed supernovae.

via Phys.org|

#astronomy #black-hole #failed-supernova