Tag

Jwst

All articles tagged with #jwst

space20 days ago•7 min saved

Chariklo’s shifting rings hint at active dynamics in the smallest ringed world

New JWST occultation data show Chariklo’s two rings have evolved: the inner ring C1R thickened while the outer ring C2R faded, suggesting real temporal evolution rather than just a viewing geometry effect. Explanations include wavelength-dependent scattering in infrared or actual material transfer, possibly aided by an unseen shepherd satellite. A follow-up visible-light occultation is needed to confirm the cause and distinguish true change from observation effects.

via Ars Technica|

#chariklo #jwst #minor-bodies

astronomy22 days ago•66 min saved

Heavy seeds ignite rapid growth, linking JWST's little red dots to overmassive black holes

Cosmological radiation‑hydrodynamic simulations show that ~10^6 solar‑mass heavy seeds can form in overdense protocluster regions under intense FUV radiation, quickly growing via brief super‑Eddington accretion to ~3×10^7 M⊙ by z ≈ 8. This unifies the high‑redshift little red dots observed by JWST with the overmassive black holes, as dense circum‑BH disks produce Balmer features and Hα emission without a traditional broad‑line region, while light‑seed remnants fail to grow similarly. The study also predicts X‑ray obscuration during early growth and potential LISA detections from BH mergers. Results are robust to changes in LW flux and higher resolution tests, offering a cohesive pathway from heavy‑seed formation to overmassive high‑z quasars.

via Nature|

#astronomy #direct-collapse #early-universe

science25 days ago•12 min saved

Hunting the Universe’s First Stars with Gravitational Lenses

Population III stars formed from pristine gas roughly 100–250 million years after the Big Bang and, if massive, burned bright for only a few million years before dying and seeding heavier elements. No individual Pop III star has been definitively identified, largely because their light is faint and rare to spot, but gravitational lensing by galaxy clusters—along with JWST’s infrared power—offers a path to detect them. Earendel, a highly magnified star behind a foreground cluster, demonstrates the lensing method, though it is not a Pop III star. Detecting a true first star would require precise lens models and spectroscopy proving a pristine, metal-free atmosphere, plus accounting for microlensing variability. A confirmed Pop III detection would illuminate the early mass distribution of the first stars and the timeline of metal enrichment, though such a star may still remain elusive across the cosmos.

via Space Daily|

#early-universe #first-stars #gravitational-lensing

science25 days ago•2 min saved

JWST Detects Record-Breaking Galaxy From 280 Million Years After the Big Bang

NASA’s James Webb Space Telescope has spotted MoM-z14, a galaxy at redshift z=14.44, dating to about 280 million years after the Big Bang—making it the most distant galaxy observed. The finding hints at a surprisingly large population of bright galaxies in the early universe and shows heavier elements like carbon and nitrogen present in such ancient systems.

via BBC Sky at Night Magazine|

#cosmic-dawn #early-galaxies #jwst

space1 month ago•11 min saved

Ancient Oxygen in a 300‑Million‑Year‑Old Galaxy Reveals Early Stellar Enrichment

ALMA detected the ionised oxygen [O III] 88 μm line in JADES-GS-z14-0, a galaxy seen when the universe was under 300 million years old (z ≈ 14.18), confirming rapid heavy‑element production by early generations of massive stars. The inferred abundances are about 5–20% of solar (around 17% in some models), indicating fast chemical enrichment, while not pinning down specific stellar histories or supernovae.

via spacedaily.com|

#alma #early-universe #jwst

space1 month ago•13 min saved

Lava world and habitable-zone companion around a red dwarf spur atmospheric studies

Two planets orbit the same red dwarf TOI-1752: a lava world (TOI-1752 b) with a 0.94‑day orbit and 1.69 Earth radii, and a cooler sub‑Neptune (TOI-1752 c) with a 32.7‑day orbit and 2.29 Earth radii in the optimistic habitable zone, about 337 light‑years away. This rare planetary pairing lets researchers directly compare atmospheric retention under different irradiation using JWST and the Ariel mission, advancing tests of whether exoplanets around M‑dwarfs can hold onto atmospheres. The system was confirmed Aug. 31, 2026 by IAA-CSIC and validated by TRICERATOPS and WATSON-Net, marking a major step for atmospheric characterization in exoplanet science.

via Space Daily|

#atmospheres #exoplanets #habitable-zone

space1 month ago•1 min saved

JWST Unveils Infrared Portrait of the Lion’s Head Nebula

NASA’s James Webb Space Telescope provides a detailed infrared view of the Lion’s Head Nebula, a planetary nebula formed as a Sun-like star shed its outer layers, leaving a hot white dwarf at the core that ionizes surrounding gas to sculpt a lion-like face, with surviving dust creating the mane; the new image helps scientists study gas-dust interactions and radiation effects in dying stars.

via NASA (.gov)|

#jwst #miri #nircam

space1 month ago•14 min saved

Nanometre-Scale Diagnosis: JWST Survives Dust Hit on Mirror Segment C3

During commissioning in May 2022, a dust-sized micrometeoroid struck JWST's primary mirror segment C3, leaving a deformation that could not be fully corrected by its actuators, but the telescope remained within optical requirements thanks to nanometre-scale wavefront sensing that diagnosed the change and guided partial correction and adjusted operations.

via Space Daily|

#jwst #micrometeoroid #mirror-deformation

science1 month ago•9 min saved

JWST Discovers a Black Hole Star Buried in Hydrogen at Cosmic Dawn

NASA’s James Webb Space Telescope spotted MoM-BH*-1, a compact, red, ultra-bright source from just a few hundred million years after the Big Bang that is too luminous for nuclear fusion. The leading model places a ~100,000-solar-mass black hole inside a dense hydrogen envelope, with accretion energy reprocessed by the surrounding gas to produce star-like light. If confirmed, this “black hole star” could reveal how massive black holes grow in the early universe and help explain JWST’s mysterious little red dots.

via SciTechDaily|

#astronomy #black-holes #cosmic-dawn

space-and-astronomy1 month ago•48 min saved

Dense mega-Earth GJ 523b challenges planetary norms with thin atmosphere

Astronomers have identified GJ 523b, a dense 'mega-Earth' about 2.5 times Earth in size and around 23 times as massive, with a surprisingly thin atmosphere. Discovered by NASA’s TESS and examined with the WIYN telescope and the James Webb Space Telescope, the planet’s high density and lack of a thick gaseous envelope defy simple formation models, leading researchers to speculate that extreme heat or a past planetary collision stripped away much of its atmosphere and to push for a clearer definition of the Mega-Earth category.

via Yahoo|

#atmosphere-loss #exoplanets #gj-523b

space-and-astronomy1 month ago•55 min saved

Triple black holes in a distant galaxy reveal rapid early-universe growth

Astronomers using the JWST have identified three active black holes in the distant galaxy J0148-4214, about 12.5 billion light-years away. Two lie at the core (80 million and 600,000 solar masses) and are 620 light-years apart, while a third, ~2 million solar masses, sits ~5,500 light-years away and may merge with the pair or escape. The system supports rapid black-hole growth in the early universe via mergers and foreshadows future low-frequency gravitational-wave detections by space-based observatories like LISA.

via Yahoo|

#black-holes #galaxy-mergers #gravitational-waves

science1 month ago•5 min saved

Water and Dust Survive Near the Milky Way's Supermassive Black Hole, JWST Finds

JWST’s mid-infrared study of the inner parsec around the Milky Way’s Sagittarius A* detects water and dust being expelled by the dying AGB star IRS 3, showing that star-produced material can endure in the harsh galactic-center environment. Models suggest IRS 3 formed farther out and migrated inward, continuing to enrich its surroundings with a bright, long-lived stellar wind; the work demonstrates that molecular material can survive near a supermassive black hole and was published in Astronomy & Astrophysics.

via ScienceAlert|

#dust #jwst #milky-way-center

space1 month ago•9 min saved

Possible Saturn-mass planet near Alpha Centauri A remains unconfirmed despite Webb hints

The James Webb Space Telescope briefly detected a faint source near Alpha Centauri A in 2024 (S1) that could be a Saturn-mass planet in the system’s habitable zone, but follow-up observations in 2025 found no comparable signal. Two 2025 papers combine imaging tests with millions of orbital simulations and conclude a real planet remains plausible, though not proven: if real, it would be a gas giant ~90–150 Earth masses orbiting around 1–2 AU with a high eccentricity, and could have slipped behind Webb’s coronagraphic blind spots between observations. Confirmation will require a future recovery of the signal or independent measurements; for now the evidence is intriguing but not conclusive.

via spacedaily.com|

#alpha-centauri-a #exoplanet #gas-giant

science1 month 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

science1 month 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