Tag

Exoplanet

All articles tagged with #exoplanet

astronomy3 days ago•8 min saved

Dense Mega-Earth Gliese 523b Defies Planet Formation Theories with Polar Orbit

Astronomers confirm Gliese 523b—a dense meg-eath about 2.55 Earth radii and 23.5 Earth masses (density ~7.8 g/cm3) orbiting the young, ~169‑million‑year‑old star Gliese 523 every 17.75 days on a highly inclined, near-polar orbit (inclination ≥71°). With little or no atmosphere, it challenges standard formation models. The planetary nature was established using NEID radial‑velocity data and TESS transits. Its enigmatic characteristics have scientists exploring scenarios such as atmospheric stripping, warped protoplanetary disks, undetected outer companions, or giant impacts that prevented thick atmosphere formation.

via Sci.News|

#astronomy #exoplanet #gliese-523b

space4 days ago•3 min saved

Dense Mega-Earth GJ 523b Defies Conventional Planet Formation

Astronomers confirm GJ 523b, a rock-dominated mega-Earth about 23 Earth masses and 2.5 Earth radii in a 170-million-year-old system, orbiting its star every 17.75 days. Its extreme density and thin atmosphere challenge standard models that would normally push such a core to become a gas giant, prompting theories like atmospheric stripping from stellar heat or a head-on collision of rocky protoplanets. This discovery provides a rare glimpse into how ultra-dense worlds form and evolve.

via geekspin|

#exoplanet #gj-523b #mega-earth

space6 days ago•159 min saved

GJ 523b: A colossal rocky world defying formation expectations

Astronomers have identified GJ 523b, an unusually dense exoplanet about 2.5 times Earth’s radius and roughly 23–24 times Earth’s mass, making it a so‑called mega‑Earth with a predominantly rocky composition and little atmosphere. Its high density challenges standard planet‑formation models that predict gas envelopes once cores reach ~20 Earth masses; explanations include atmospheric loss or a giant‑impact origin. The planet orbits its star every 17.75 days in a relatively young system (~170 million years old), with the discovery arising from NASA’s TESS data and ground‑based WIYN follow‑up observations.

via Space|

#density #exoplanet #gj-523b

space9 days 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

space24 days ago•11 min saved

Glimpse of a Hidden Giant: Beta Pictoris d Emerges from Archival Data

Astronomers have directly imaged a faint gas giant, Beta Pictoris d, orbiting the young nearby star Beta Pictoris—first seen in archival VLT SPHERE data and independently confirmed by JWST. Weighing roughly 2.4 Jupiter masses and orbiting at about 26 AU with a ~91-year period, it is the faintest exoplanet imaged from the ground (100x fainter than Beta Pictoris b). JWST spectra revealed methane, carbon monoxide, and water vapor, helping distinguish the planet from the debris disk. This discovery makes Beta Pictoris the second system with three directly imaged planets and offers a valuable lab for studying planet formation and disk sculpting, with ELT prospects for uncovering more hidden worlds.

via SciTechDaily|

#beta-pictoris-d #beta-pictoris-system #direct-imaging

science24 days ago•7 min saved

Astronomers Detect Likely Exomoon Orbiting Brown Dwarf, Blurring Boundaries

An international team using the ESO Very Large Telescope detected a moonlike body orbiting the brown dwarf CD-35 2722 B about 73 light-years away, with a roughly 170-day orbit and a mass of at least 0.9 Jupiter—about 2.5% of the brown dwarf’s mass. Described as an exosatellite rather than a moon, this is the first satellite evidence around a brown dwarf found via the Doppler method, though its exact classification remains under discussion. The discovery challenges traditional moon definitions and could influence theories of planet formation and tidal heating, with future telescopes potentially revealing smaller exomoons.

via WIRED|

#brown-dwarf #doppler-method #exomoon

space26 days ago•3 min saved

Rocky exoplanet LHS 1140 b shows helium escape, reshaping habitability hunt

Ground-based spectroscopy captured helium escaping from the upper atmosphere of rocky exoplanet LHS 1140 b, confirming it retains an atmosphere in a star‑active red-dwarf system and suggesting a layered atmosphere; the atmospheric loss appears tied to stellar activity, making LHS 1140 b a high-priority target for JWST/Hubble to search for water and other habitability indicators.

via Futura, le média qui explore le monde|

#atmosphere #exoplanet #habitablezone

space1 month ago•9 min saved

Astronomers spot a moon-like world around a brown dwarf, hinting at the first exosatellite beyond our solar system

Astronomers report what could be the first plausible detection of an exosatellite—a planet-mass body orbiting a substellar companion around a brown dwarf rather than a star—found by watching tiny wobbles in the brown dwarf; if confirmed, it would expand our understanding of moons beyond our solar system and was described in a Nature paper.

via The Independent|

#astronomy #brown-dwarf #exoplanet

space-and-astronomy1 month ago•49 min saved

First Exomoon Detected: Jupiter-Mass Moon Orbits a Brown Dwarf

Astronomers have identified the first known exomoon—a Jupiter-mass satellite orbiting a brown dwarf (CD-35 2772) about 71 light-years away—discovered via radial velocity measurements, challenging how we classify planets and moons and signaling more exomoon hunts with the forthcoming ELT.

via Yahoo|

#brown-dwarf #eso #exomoon

space1 month ago•13 min saved

Blue Sky, Fire Winds: Glass Rain on the Exoplanet HD 189733b

HD 189733b is a nearby hot Jupiter about 63 light-years away that appears deep blue from space not because of oceans but due to a scorching dayside atmosphere where silicate particles melt into glassy droplets that scatter blue light. It orbits extremely close to its star (about 2.9 million miles) in 2.2 days and is tidally locked, with dayside temperatures around 2000°F and winds that have been measured up to 4,500 mph (with later data suggesting even faster speeds). The blue color serves as a warning sign of extreme atmospheric chemistry and dynamics, making this planet a valuable observable laboratory rather than a habitable world.

via Space Daily|

#atmosphericwinds #exoplanet #hd-189733b

space1 month ago•5 min saved

Helium Signals Long-Lived Atmosphere on Rocky Exoplanet in Habitable Zone

Astronomers detected a helium escape signal from LHS 1140 b, a rocky planet in its star’s habitable zone about 48 light-years away, confirming it retains an atmosphere that may have persisted for billions of years and making it a prime target for studying Earth-like atmospheres from the ground.

via ScienceDaily|

#atmosphere #exoplanet #habitable-zone

space1 month ago•6 min saved

Webb Telescope Reveals Hidden Giant Planet in the Beta Pictoris System

Using JWST’s NIRSpec and follow-up imaging from ESO’s VLT, astronomers detected Beta Pictoris d by its atmospheric spectrum, a third planet in the bright Beta Pictoris system—discovered via spectroscopy rather than direct imaging and independently confirmed, highlighting a new way to find worlds hidden in dusty disks.

via PetaPixel|

#beta-pictoris #debris-disk #exoplanet

science1 month ago•52 min saved

Rocky exoplanet in habitable zone shows it can hold onto an atmosphere

Astronomers detected helium escaping from LHS 1140 b, a rocky super‑Earth in the habitable zone of a cool red dwarf about 48 light‑years away, marking the strongest evidence yet of an atmosphere on a rocky world outside our solar system. Using the WINERED spectrograph during a transit, they observed a helium absorption signal for LHS 1140 b (but not for its closer neighbor LHS 1140 c), implying a retained upper atmosphere despite stellar radiation. The finding, published in Science, suggests some rocky planets around red dwarfs can hang onto atmospheres for billions of years, though it does not confirm habitability or the full atmospheric composition; future observations will seek other gases and features like oceans to assess potential habitability.

via Yahoo|

#atmosphere #exoplanet #habitable-zone

science1 month ago•46 min saved

Atmosphere detected around rocky exoplanet in star's habitable zone

Researchers have detected helium in the upper atmosphere of LHS 1140 b, a rocky planet about 48 light-years away in the habitable zone of a red dwarf, marking the first confirmed atmosphere around an Earth-like world outside our solar system; while helium alone wouldn’t support life, the finding shows such planets can retain atmospheres and may host other gases deeper down, bringing us a step closer to identifying habitable worlds.

via Yahoo|

#atmosphere #exoplanet #habitable-zone

science1 month ago•4 min saved

Nearby Rocky World LHS 1140-b Reveals Helium Atmosphere in Habitable Zone

Scientists detected a helium-dominated atmosphere around the rocky exoplanet LHS 1140-b, a planet in the habitable zone about 48 light-years away, marking the first direct evidence that such worlds can retain an atmosphere and potentially host liquid water and Earth-like life. The finding comes from WINERED observations on the Magellan telescope and suggests atmospheric escape can vary over time, while a nearby planet (LHS 1140-c) shows no atmosphere.

via 404 Media|

#atmosphere #exoplanet #habitable-zone