Tag

Astronomy

All articles tagged with #astronomy

astronomy1 hour ago•8 min saved

Orion Nebula Exposes Complex Shells From Repeated Stellar Feedback

Using combined 21 cm HI observations from the VLA and FAST, researchers produced the sharpest radio maps of neutral hydrogen around the Orion Nebula, revealing giant expanding shells, cavities, and a four-light-year protrusion inside a second cavity. The structures imply the region was sculpted by multiple generations of massive stars rather than a single bubble, and the HI mass is revised down from ~1000 to ~100 solar masses. Published in Astronomy & Astrophysics as part of the NeAtHood project, the findings challenge simple star-formation models and showcase the power of modern radio interferometers, hinting at more hidden structure to come.

via Sci.News|

#astronomy #neutral-hydrogen #orion-nebula

technology1 hour ago•3 min saved

FCC Approves Sun-Reflecting Orbital Test, Sparking Astronomers’ Alarm

The FCC authorized Reflect Orbital’s Eärendil-1, a 142‑kg satellite that will deploy an 18-meter reflector to redirect sunlight to nighttime regions for testing, with potential uses from construction lighting to boosting solar farm output. Proponents say it could advance space testing and utility lighting, but astronomers and environmentalists warn it could brighten the night sky, disrupt diurnal cycles, and interfere with telescopes and wildlife. The FCC said environmental and astronomical impacts fall outside its review but noted commitments to NASA/NSF collaboration and community consultation; public comments were largely critical, and petitions for a broader environmental assessment have been filed as the company contemplates thousands of future satellites.

via SpaceNews|

#astronomy #environmental-impact #fcc

science12 hours ago•11 min saved

Cassini hints Saturn’s rings are a recent, fading feature

Cassini measurements imply Saturn’s rings are relatively young (roughly 10–400 million years old) and are currently draining into the planet, with ring rain alone potentially clearing them in about 100 million years; the exact age and loss rate are still debated, but the data tilt toward a transient, recently formed ring system that may soon disappear, with future JWST and ground observations expected to refine the timeline.

via Space Daily|

#astronomy #cassini #ring-rain

technology20 hours ago•2 min saved

Orbital Sunbeam: FCC greenlights Reflect Orbital's demo mirror satellite

The FCC has granted approval for Reflect Orbital’s Eärendil-1 demonstration satellite, which will deploy an 18-by-18 meter aluminized Mylar reflector to direct sunlight onto Earth from a near-polar orbit around 625 km up. The test aims to prove “sunlight on demand” for solar farms and other uses, with a broader constellation contemplated in the future, but the agency only approved radio operations for the demo and did not authorize a full constellation. Critics warn about potential interference with ground-based astronomy, wildlife, aviation, sky brightness, and the growing debris risk, while disposal within 25 years is required; SpaceX is slated to carry the first two demos, and further approvals will be needed for expansion.

via TechSpot|

#astronomy #reflective-mirror #satellites

technology1 day ago•6 min saved

FCC Clears Earendil-1 Space Mirror Test to Reflect Sunlight Back to Earth

The FCC approved a single demonstration satellite, Earendil-1 by Reflect Orbital, which uses a 60-by-60-foot mirror to reflect sunlight onto Earth over a ground area roughly 3 miles wide. The company envisions benefits like powering solar farms at night or aiding disaster relief, but astronomers and environmental groups raised concerns, contributing about 1,800 public comments. The agency says this is a limited, short-term test and did not require an environmental review; Reflect Orbital plans to launch later this year and pursue independent research and NSF coordination.

via PCMag|

#astronomy #light-pollution #regulation

science1 day ago•20 min saved

Cosmic cotton candy: two Jupiter-sized exoplanets revealed as featherweight 'super-puffs'

Astronomers have identified two Jupiter-sized exoplanets, TOI-791 b and TOI-791 c, about 1,100 light-years away, that are ultralow-density 'super-puffs,' with densities far lower than Jupiter and likely hydrogen/helium atmospheres. Their puffiness, comparable to shaving foam or cotton candy, makes them some of the lightest known planets and challenges standard formation theories. Observations from Antarctica helped determine their densities, and their orbits may be in a mean-motion resonance, implying formation in gas-rich regions farther from their star.

via Metro.co.uk|

#astronomy #exoplanets #science

space1 day ago•93 min saved

Milky Way could be bigger and more lopsided after new arm measurements

New gamma-ray burst echoes mapped two of the Milky Way’s largest spiral arms, suggesting they’re about 10% farther from Earth than previously thought. The finding implies the galaxy may be wider and more massive, with asymmetry in its shape, prompting scientists to revisit estimates of the Milky Way’s size and mass.

via Live Science|

#astronomy #galaxy #gamma-ray-bursts

space3 days ago•104 min saved

Earth Could Outsmart the Sun's Final Farewell, New Study Finds

New models of how aging stars interact with nearby planets suggest Earth could avoid being engulfed as the Sun swells into a red giant. The study finds that weaker tidal forces and mass loss from the Sun could allow Earth (and Mars) to migrate outward, while Mercury and Venus are still doomed to be swallowed. The outcome depends on uncertain mass-loss rates during the Sun’s final stages; with current data, Earth’s survival is possible but not guaranteed, and more observations of sun-like giants are needed, the team reports in Astronomy & Astrophysics.

via Space|

#astronomy #earth #planetary-systems

science3 days ago•6 min saved

Hubble at a crossroads: extend into the 2030s or bow out

NASA is weighing options to extend the Hubble Space Telescope into the 2030s by moving it to a higher, more stable orbit or to decommission it via a robotic mission. White papers and science-priority pitches are due in July, with recommendations to NASA and Congress later this year. Hubble’s ultraviolet/optical data remain uniquely valuable and complement JWST, aiding studies of galaxy evolution, star formation, dark energy, and exoplanet atmospheres. With the Habitable Worlds Observatory not launching before 2040, keeping Hubble operational for as long as feasible is seen as crucial for the next decade.

via Nature|

#astronomy #habitable-worlds-observatory #hubble-space-telescope

astronomy3 days ago•8 min saved

Isotopes Trace Interstellar Visitor 3I/ATLAS to Ancient, Metal-Poor Disk

Astronomers using ESO's Very Large Telescope measured carbon and nitrogen isotope ratios in the interstellar comet 3I/ATLAS, finding carbon-12/carbon-13 ~151 and nitrogen-14/nitrogen-15 ~363. These values are higher than typical solar-system comets, suggesting formation in the cold outer disk around an older, metal-poor star, consistent with isotope-selective chemistry in such environments. The results, published online July 6, 2026 in Nature Astronomy, provide a rare glimpse into material from another planetary system and the efficiency of planetesimal formation around ancient stars.

via Sci.News|

#3iatlas #astronomy #interstellar-object

science4 days ago•3 min saved

Milky Way Arms Extend Further Than Previously Thought

Astronomers used light echoes from gamma-ray bursts observed by NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton to geometrically measure distances to dust clouds in the Milky Way’s spiral arms, finding the Outer and Outer Scutum-Centaurus arms are about 10% farther away than previously thought; the method could revise estimates of the Milky Way’s mass and arm structure, with the most distant arm’s dust cloud about 3,500 light-years thick and only a handful of usable GRBs observed over 25 years.

via Gizmodo|

#astronomy #dust-clouds #gamma-ray-bursts

astronomy4 days ago•11 min saved

Second-Generation Black Holes: Gravitational Waves Hint at Hierarchical Mergers

Analyses of GWTC-4.0 from multiple groups converge on a high-mass subpopulation of merging black holes consistent with hierarchical mergers, where at least one black hole is the remnant of a prior merger. Second-generation black holes should be roughly twice as massive as first-generation ones, with spins near 0.7 and random orientations; a transition around 40–45 solar masses marks the shift from low-spin to higher-spin populations. These results, obtained with diverse population models focusing on effective spins, bolster the case that dense environments produce recycled black holes and have implications for the mass gap and black-hole growth, with sharper insights expected as detectors improve.

via American Physical Society|

#astronomy #black-holes #gravitational-waves

science4 days ago•3 min saved

New Path for Star Death Found Near Galactic Cores

Astronomers linking a long gamma-ray burst to the merger of two compact objects near a galaxy’s central supermassive black hole reveal a new, fourth pathway for how stars can die in the universe’s densest regions, with future work aiming to detect accompanying gravitational waves using observatories like the Vera C. Rubin Observatory.

via BBC Sky at Night Magazine|

#astronomy #gamma-ray-burst #gravitational-waves

astronomy5 days ago•89 min saved

JWST maps the cosmos with its largest, most detailed 3D survey

Using the COSMOS-Web program, the James Webb Space Telescope has produced the largest-ever 3D map of the universe, charting about 164,000 galaxies over a 255-hour survey to reveal the cosmic web’s skeleton from the present back to when the universe was under 1 billion years old. The map shows dense regions fostering early galaxy growth and, later, environmental quenching in massive galaxies—likely driven by massive dark matter halos and feedback from supermassive black holes—providing new insight into how the large-scale structure of the cosmos evolved. The COSMOS-Web galaxy catalog is publicly available for researchers.

via Live Science|

#astronomy #cosmic-web #cosmos-web

space5 days ago•6 min saved

Cosmic Web Persists Across Vast Scales, Challenging Uniformity

A Nature study analyzing 47 million galaxies from the DESI survey finds coherent patterns in the cosmic web extending across billions of light-years, suggesting the universe may not be perfectly homogeneous or isotropic on the largest scales. The result challenges a key cosmological assumption and could prompt revisions to models of dark matter, gravity, and structure formation, though independent replication with larger datasets is needed before firm conclusions.

via WIRED|

#astronomy #cosmic-web #cosmology