Tag

Gravitational Collapse

All articles tagged with #gravitational collapse

space-and-spaceflight10 days ago•17 min saved

Gravastar Idea: A Dark-Energy ‘Mini-Universe’ Inside a Black Hole Mimic

Physicists propose gravastars—ultra-compact stars with a thin shell of ordinary matter and an interior powered by dark energy—that externally resemble black holes but lack singularities or event horizons. A new model shows how such objects could form from gravitational collapse and, in the process, trigger a Big Bang–like expansion inside a self-contained mini-universe. The scenario hinges on ideal, finely tuned conditions and does not replace black holes as the default outcome of collapse.

via Gizmodo|

#black-holes #dark-energy #general-relativity

space4 months ago•5 min saved

Snowman-Shaped Kuiper Belt Object Reveals a Quiet Route to Planet Formation

A new study shows Arrokoth-like bilobed objects can form directly from the gravitational collapse of small pebbles in the early solar system, producing the snowman shape without violent mergers and suggesting such binaries may be more common in the Kuiper Belt; simulations found several instances of this outcome, supporting a calmer path to planet formation.

via The Daily Galaxy|

#arrokoth #contact-binary #gravitational-collapse

science4 months ago•3 min saved

Gentle Gravity Shapes Peanut-Shaped Kuiper Belt Objects

A new study using 54 simulations of pebble clouds (each with 100,000 particles) shows that peanut-shaped Kuiper Belt objects like Arrokoth can form through gentle gravitational collapse rather than violent impacts. About 29 of the simulations produced Arrokoth-like contact binaries, supporting the idea that such objects arise from mild formation processes, though only about 3% of the planetesimals formed a contact binary in the model, indicating more work is needed.

via Gizmodo|

#arrokoth #contact-binary #gravitational-collapse

space4 months ago•3 min saved

Pebble-cloud collapse may forge Arrokoth’s snowman shape

New computer simulations show that gentle gravitational collapse of pebble clouds in the early solar system can produce double-lobed, snowman‑like bodies such as Arrokoth, via two small planetesimals merging at about 5 meters per second to form a contact binary. The results support a gentle formation path for Kuiper belt objects, though the model predicts about 4% of objects form this way, while telescopic surveys suggest higher fractions, implying other formation routes may also contribute.

via The Guardian|

#arrokoth #contact-binary #gravitational-collapse

science7 months ago•19 min saved

Revolutionary Theory Challenges 60-Year Black Hole Paradigm

A new theory questions the traditional view of black holes, suggesting they may never fully form but only approach their event horizons asymptotically, which resolves longstanding paradoxes and emphasizes the importance of causal structure in observations.

via SciTechDaily|

#black-holes #event-horizon #general-relativity

astronomy2 years ago•3 min saved

"Lonely Ageing Brown Dwarfs: Hubble's Surprising Discovery"

A recent survey using the Hubble Space Telescope has found that ageing brown dwarfs, which are larger than Jupiter but smaller than stars, are less likely to have companions as they get older. This suggests that binary pairs of brown dwarfs do not survive over time, likely due to the weak gravitational hold between them and the disruptive influence of passing stars. The survey provides evidence that most brown dwarfs remain single for the majority of their long existence, supporting the theory that they are born the same way as stars but do not have enough mass to sustain nuclear fusion.

via ESA/Hubble|

#astronomy #binary-systems #brown-dwarfs

science2 years ago•6 min saved

Unraveling the Mysteries of Gravitational Wave Collapse

A recent study by an international research collaboration has resolved long-standing puzzles in the gravitational collapse of gravitational waves. The study found agreement among three independently conducted numerical simulations, shedding light on critical phenomena and the properties of general relativity. The researchers discovered that the collapse of gravitational waves does not exhibit universality, but approximate self-similarity. The findings could lead to further studies and a better understanding of the nature of critical collapse and the formation of black holes.

via Phys.org|

#black-holes #critical-phenomena #gravitational-collapse

astronomy2 years ago•3 min saved

The Fate of the Sun: Black Hole or Eternal Star?

The sun will not become a black hole when it dies because it lacks the necessary mass. Stars with initial masses greater than 20 to 25 times that of the sun have the potential to undergo gravitational collapse and form black holes. The sun will instead become a white dwarf, a dense, Earth-size star. As it reaches the end of its life, the sun will expand into a red giant, possibly engulfing the inner planets, including Earth, before shedding its outer layers and leaving behind a smoldering core.

via Livescience.com|

#astronomy #black-holes #gravitational-collapse