Latest astronomy nouvelles

Key findings

• Three velocity components were identified in the hydrogen-like and helium-like iron lines, with maximum velocities of 2000–3000 k...

Pulsars are highly magnetised, rapidly rotating neutron stars — the ultra-dense remnants left behind when a massive star ends its life in a supernova explosion. They emit narrow beams of radio waves that sweep across space like a lighthouse, producing precise pulses detectable by radio telescopes on Earth. Some pulsars display a puzzling behaviour called nulling, where their radio emission abruptly becomes undetectable, or drops far below its nor...

AD Leonis (AD Leo) is an active M-dwarf — a small, cool red star — located about 16 light-years from Earth that is known for producing frequent and energetic flares. Stellar flares are intense, brief brightenings caused by magnetic reconnection, a process in which tangled magnetic field lines snap and realign, releasing a burst of energy as light across many wavelengths, similar to solar flares but often far more powerful relative to the star's s...

Gliese 436 b is a warm Neptune — a planet roughly the size and mass of Neptune — orbiting the red dwarf star Gliese 436, located about 33 light-years from Earth. Astronomers used the Keck II telescope on Mauna Kea, Hawaii, fitted with an instrument called KPIC (Keck Planet Imager and Characterizer). KPIC routes starlight through a hair-thin single-mode optical fiber before feeding it into a high-resolution spectrograph — a technique that suppress...

Astronomers comparing new James Webb Space Telescope data with 20-year-old Spitzer observations have discovered significant changes in the dusty, planet-forming disks surrounding two young stars, Sz 96 and IP Tau. The study found that the infrared light emitted by silicates—minerals similar to sand or rocks—shifted in brightness by up to 35%, suggesting that the inner structure of these disks is physically changing over time. Furthermore, the ...

Researchers using the James Webb Space Telescope have analyzed the atmosphere of the sub-Neptune planet HD 15337 c, which is about 2.5 times the size of Earth. The study revealed a 'featureless' spectrum, meaning the planet's atmosphere is likely very thick, enriched with heavy elements, or covered in high-altitude clouds and haze. Interestingly, the planet arrived for its transit earlier than expected, suggesting the presence of an undiscove...

Using the James Webb Space Telescope, astronomers have examined the atmosphere of TOI-260 b, a planet roughly 1.7 times the size of Earth that sits in the mysterious 'radius valley'—a gap where few planets are found. The observations revealed a mostly flat spectrum, suggesting the planet might have a very heavy atmosphere enriched with elements other than hydrogen and helium, or perhaps hidden by high-altitude clouds. While a small potential s...