Tag

Early Universe

All articles tagged with #early universe

science13 hours ago•4 min saved

Webb dots reveal early supermassive black holes in tiny galaxies

A Nature Astronomy study using JWST data from the COSMOS-Web region suggests the mysterious 'little red dots' are the earliest supermassive black holes, residing in very compact host galaxies that contain about 1 billion stars. The host galaxies are ~4% of the Milky Way’s size and contribute only ~10% of the dots’ light, while the central black holes (roughly 10^7–10^9 solar masses) dominate the emission. This implies black holes may grow most of their mass before their galaxies form most of their stars, shedding light on how black holes and galaxies co-evolve; the team analyzed 217 JWST images across a region about three times the Moon’s size to measure host properties and applied PSF subtraction to isolate the faint hosts.

via The Conversation|

#astronomy #black-holes #early-universe

science1 day ago•2 min saved

Hidden Low-Mass Stars Make Early Massive Galaxies Much Heavier Than Thought

Webb Space Telescope observations (with VLT data) published in Nature Astronomy reveal a hidden population of small, faint stars in nine of the universe’s most massive early galaxies, implying those systems are far more massive than previously estimated. By analyzing subtle spectral signatures of low-mass stars, researchers found many more dwarfs than bright stars alone would suggest, with one galaxy formed within roughly 1.5 billion years after the Big Bang potentially four times heavier than thought. This challenges existing models of early galaxy growth and could have implications for planet formation around low-mass stars in the ancient universe.

via Gizmodo|

#astronomy #early-universe #galaxies

space4 days ago•6 min saved

One-Hour Light Bender Hints at Primordial Black Hole in Milky Way Halo

A star in the Large Magellanic Cloud briefly brightened for about an hour in 2019 due to gravitational microlensing by an unseen object nicknamed Phoebe. Its mass is estimated at roughly three lunar masses, too light to be a planet or stellar black hole. Analyses favor Phoebe being a dark-matter object in the Milky Way halo, with a primordial black hole as a leading exotic possibility; if confirmed, it would be among the oldest objects in the universe. Alternatives include a free-floating planet in the Milky Way or in the LMC. The event highlights microlensing as a tool to probe dark matter and compact objects.

via SciTechDaily|

#dark-matter #early-universe #gravitational-microlensing

science4 days ago•159 min saved

Dark Photons Could Still Be Dark Matter, Say New Simulations

New computer simulations show that the conversion of dark photons to ordinary photons in the early universe may not heat the cosmos as much as previously thought, reopening expanded parameter space for dark photon dark matter and potentially guiding new experimental searches.

via Space|

#cosmology #dark-matter #dark-photons

space4 days ago•138 min saved

JWST spots solar-system-sized 'black hole star' in the early universe

Astronomers using the James Webb Space Telescope have spotted MoM-BH*-1, a solar-system-sized, red, gas-enshrouded object about 660 million years after the Big Bang. Interpreted as a black hole star—a massive black hole wrapped in a cocoon of dense gas—the object could be the best evidence yet for this hypothetical class and may explain the mysterious 'little red dots' seen by JWST. The central black hole could weigh up to about 100,000 solar masses, and while previous candidates existed, MoM-BH*-1 is farther away and thus more informative; further observations are needed to confirm the model and understand how such objects form.

via Live Science|

#black-hole-star #early-universe #james-webb-space-telescope

space-and-astronomy4 days ago•58 min saved

Webb spots solar-system-sized dot likely a black hole star from the dawn of the universe

The James Webb Space Telescope identified MoM-BH*-1, a solar-system-sized, ruby-red dot seen about 660 million years after the Big Bang, proposed as a new object class: a black hole star—a dense shell of gas around a massive black hole. If confirmed, it would be the strongest evidence yet for this type of object and could help explain the enigmatic “little red dots” JWST has found. The object may host up to ~100,000 solar masses, with its Balmer-break spectrum indicating a dust-free, hydrogen/helium gas cocoon rather than ordinary starlight; further observations and modeling are needed to verify this interpretation.

via Yahoo|

#black-hole-star #early-universe #james-webb-space-telescope

astronomy7 days ago•4 min saved

Ancient Milky Way merger revealed by globular-cluster fossils

A Nature Astronomy study uses precise ages and metallicities of Milky Way globular clusters to reconstruct the Galaxy’s early growth, revealing three distinct age–metallicity tracks and an ancient major merger (progenitor Low-energy–Kraken–Heracles) about 12 billion years ago with roughly 500 million solar masses, depositing most material in the inner Milky Way. This refines the Milky Way’s formative timeline and complements JWST views of distant galaxies by tying together fossil stars and early-universe observations.

via The Conversation|

#astronomy #early-universe #gaia-sausage-enceladus

space7 days ago•3 min saved

James Webb Spots a New Class of Star Fueled by Black Holes

Using the James Webb Space Telescope, scientists identified a new object class—'black hole stars'—dense gas clouds fully enveloping a black hole that are powered by the black hole’s energy rather than fusion, yielding a brightness about 100 billion times that of a normal star. These objects appear as extremely bright red dots in Webb’s deep-field images from the cosmic dawn, implying such systems formed in the early universe and could shed light on how supermassive black holes arise; they are not accretion disks and require further study.

via jalopnik.com|

#accretion-disk #black-hole-star #cosmic-dawn

astronomy8 days ago•14 min saved

Webb uncovers a buried black-hole-star in the early universe

JWST images of MoM-BH*-1, a red point at z ≈ 7.7569 (about 660 million years after the Big Bang), reveal luminosity near 100 billion Suns powered not by fusion but by an accreting black hole enshrouded in a dense, nearly dust-free gas cocoon. Spectra show an extreme Balmer break and broad hydrogen lines that support a black-hole–star model, with the envelope spanning roughly 10–100 AU and gas densities ~10^11 cm^-3, column ~10^25.8 cm^-2; the black hole mass is likely ~10^6–10^7 solar masses. This finding hints at rapid black-hole growth in the early universe and helps explain the population of little red dots as buried black holes, though future observations are needed to test the cocoon scenario.

via Space Daily|

#accreting-black-hole #astronomy #balmer-break

science9 days ago•5 min saved

JWST Spots a Black Hole Star Lighting Up the Early Universe

Using the James Webb Space Telescope, scientists describe MoM-BH*-1—a black hole embedded in a massive, luminous gas envelope that glows bright red about 660 million years after the Big Bang. The object emits energy far exceeding normal stars, while dense surrounding gas absorbs light in a way that makes the source appear star-like. This provides evidence for the existence of black hole stars and may explain mysterious red spots seen in the early universe.

via WIRED|

#black-hole-star #early-universe #james-webb-space-telescope

space9 days ago•13 min saved

Ancient Quasar Enveloped by a Vast Water Vapor Halo

Astronomers modeling a diffuse reservoir of water vapor around the gravitationally lensed quasar APM 08279+5255 (redshift 3.91) report an inventory equivalent to about 140 trillion times Earth’s oceans, and a total water mass around 100,000 solar masses; the figure is model-dependent and hinges on lens magnification, gas excitation by infrared radiation, and the assumed molecular-gas mass. The detection relies on multiple water emission lines rather than a direct image or measurement of liquid water, and places water in the environment of a feeding supermassive black hole when the universe was about 1.6 billion years old, roughly 12 billion years in light-travel time. The result highlights water as a tracer of physical conditions in the early universe and underscores the uncertainties introduced by gravitational lensing.

via Space Daily|

#apm-082795255 #early-universe #gravitational-lensing

science9 days ago•2 min saved

James Webb Spots a New Cosmic Class: a Black Hole Star Wrapped in Gas

Using the James Webb Space Telescope, researchers identified MoM-BH*-1—a black hole at its core surrounded by a dense gas shell that makes it look star-like, with about 100,000 solar masses and emitting energy about 100 billion times that of a typical star; it formed within 700 million years after the Big Bang. This discovery suggests many of the faint red dots seen in the early universe could be black hole stars embedded in young galaxies, potentially reshaping ideas about early black holes and galaxy growth.

via Futurism|

#black-hole-star #early-universe #james-webb-space-telescope

space-and-astronomy10 days ago•48 min saved

Webb Uncovers a Black Hole Star: The Cosmos’ New Object Class

Using the James Webb Space Telescope, scientists have identified MoM-BH*-1—a black hole star about 100,000 solar masses formed less than 700 million years after the Big Bang. Its center is a black hole that relentlessly accretes matter, emitting about 100 billion times more energy than a typical star, while a dense gas shell makes it appear star-sized. The finding suggests other so-called 'Little Red Dots' could be black hole stars, potentially reshaping our understanding of early galaxies and black hole growth.

via Yahoo|

#astronomy #black-holes #early-universe

science11 days ago•3 min saved

Cosmic Oddity: JWST Identifies a One-in-a-Billion Black-Hole Star

Astronomers using the James Webb Space Telescope have identified MoM-BH*-1, a rare hybrid object that blends a star-like gas cloud with a black hole about 100,000 solar masses. It emits energy far exceeding typical stellar formations and is about 100 billion times brighter than the average star, even outshining its host galaxy. This “black-hole star” could explain the little red dots seen in JWST images from the dawn of the universe and may shed light on how the first cosmic structures formed; researchers will continue studying its size and atmospheric composition with JWST starting in December.

via nypost.com|

#black-hole-star #cosmology #early-universe

science12 days ago•159 min saved

JWST uncovers a distant naked black-hole-star, offering clues to the little red dots

Astronomers using the James Webb Space Telescope’s Mirage/MoM survey discovered MoM-BH*-1, the farthest known naked black-hole-star. Its accretion-powered glow lights a surrounding gas cloud, and its proximity to a young, high-redshift galaxy suggests such objects could masquerade as faint galaxies in JWST observations. This finding supports the idea that black-hole stars may be key engines in the early universe and could illuminate why the JWST images show the mysterious little red dots; the team estimates MoM-BH*-1 could eventually merge with its host galaxy in about 100 million years, potentially shedding light on the birth of quasars.

via Space|

#black-hole-star #early-universe #jwst