New Webb and Hubble data not only confirm the existence of two distinct populations of stars in the ancient stellar system Terzan 5, once classified as a globular cluster, but also provides evidence for two more recent rounds of star formation.
The post Astronomers Find Four Separate Generations of Stars in ‘Globular Cluster’ Terzan 5 appeared first on Sci.News: Breaking Science News.
For the first time, astronomers have distinguished between the morning and evening atmospheres of a single planet, revealing two remarkably different environments at its edges. WASP-121 b is a gas giant that orbits extremely close to its star, resulting in one hemisphere exposed to temperatures approaching 2,500 degrees Celsius while the opposite side remains in constant darkness.
A research team from the Max Planck Institute for Astronomy used the James Webb Space Telescope to provide observational evidence for a phenomenon that models had previously predicted. The boundary regions between day and night on tidally locked planets can exhibit distinct temperatures and chemical compositions.
The recent findings appeared in a study published in Nature Astronomy.
WASP-121 b is part of a group of gas giants known as hot Jupiters. These massive planets orbit their stars in just a few days and eventually become locked in place by gravity. Tidal forces keep one side facing the star at all times, while the other side never sees daylight.
“WASP-121 b is particularly extreme,” said co-author Tom Evans-Soma of the University of Newcastle, Australia. “Average temperatures on the dayside hemisphere are around 2,770 Kelvin, while those on the nightside are closer to about 1,000 Kelvin.”
The difference in temperature between the two hemispheres, which is about 1,775 degrees Celsius, makes WASP-121 b one of the most thermally extreme exoplanets known. The regions at the boundary between day and night, called terminators, are where the planet experiences constant morning or evening conditions. Scientists expected these areas to have different atmospheric properties, but only with the precision of JWST could these differences be directly observed.
The researchers used a method based on the planet’s transit across its star to study these differences. As WASP-121 b passes in front of its star, it rotates by about 30 degrees, which means that different parts of its atmosphere can be observed during each transit. By tracking how infrared starlight filters through the atmosphere over time, the team reconstructed how temperature and chemical composition change across different longitudes.
“By measuring how starlight absorption changes as WASP-121 b rotates, we probe its atmosphere longitude by longitude,” said lead author Cyril Gapp of MPIA. The observations not only confirmed what models had predicted, but also showed that the differences between the two terminators are even greater than expected.
The evening side of the planet’s terminator absorbs more starlight than the morning side. Powerful eastward winds sweep heat from the scorching dayside toward the nightside, with the evening region getting the first blast of this warmth. This extra heat causes the atmosphere there to puff up, allowing it to absorb even more starlight, as the observations showed.
Chemical measurements backed up these findings. Carbon monoxide absorption increased as the hotter regions of the evening came into view near the end of the transit. Water showed a different pattern. Rather than simply decreasing with higher temperatures, the researchers interpret the result as evidence that water molecules in the upper atmosphere are breaking apart, likely due to the intense heat at the evening terminator. This points to a real chemical change, not just a shift in molecular location.
The morning side shows a different environment. Although models predicted a difference between the two terminators, they did not fully explain why the morning side appears cooler and more opaque. The most likely explanation involves clouds that are unlike those on Earth.
At the morning terminator, air comes in from the cold nightside. Temperatures may be low enough for silicate and mineral compounds to turn into tiny particles, forming clouds that block infrared radiation from below. This makes the atmosphere appear cooler than it really is underneath.
When the team adjusted their models to account for these clouds, the results more closely aligned with their observations. Still, confirming exactly how these clouds form and behave will require more advanced modeling, as cloud formation and evaporation in such extreme environments remain a major puzzle in exoplanet science.
WASP-121 b has been the subject of previous studies, but JWST now enables astronomers to examine its atmosphere in detail, section by section. This approach is now also available for use with other exoplanets.
The team has already found other ultra-hot gas giants with the right temperatures and orbits for similar analysis. Using this method on other planets will help astronomers compare atmospheric conditions and deepen our understanding of extreme planetary environments.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.
Using Webb’s NIRCam and NIRSpec instruments, astronomers have obtained the deepest spectrum ever taken of a little red dot.
The post Webb Delivers Strongest-Ever Case for ‘Black Hole Stars’ Lurking in Early Universe appeared first on Sci.News: Breaking Science News.
A supermassive black hole 6 billion times the mass of the Sun lurks in MRG-M0138, a gravitationally lensed quiescent galaxy seen when the Universe was just 3 billion years old, according to an analysis of data collected by the NIRSpec Integral Field Spectrograph onboard the NASA/ESA/CSA James Webb Space Telescope.
The post Webb Weighs Most Distant Inactive Black Hole Ever Found appeared first on Sci.News: Breaking Science News.
Using the spectral data from the Mid-Infrared Instrument (MIRI) onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers have detected methane on 3I/ATLAS.
The post Webb Detects Methane on Interstellar Comet 3I/ATLAS appeared first on Sci.News: Breaking Science News.
Pela primeira vez, há sinais reais de que o Universo terá evoluído de forma muito diferente do que se pensava. A hipótese de os buracos negros gigantes terem surgido antes das galáxias já não parece apenas ficção científica e pode obrigar a reescrever parte da história cósmica.
The post O que surgiu primeiro: o buraco negro ou a galáxia? James Webb pode ter a resposta appeared first on Tek Notícias.
Astronomers using the NASA/ESA/CSA James Webb Space Telescope have found an enormous black hole in the early Universe that appears to predate its own host galaxy, raising fresh questions about how the cosmos’ first supermassive monsters were born.
The post Webb Spots Supermassive Black Hole Older Than Its Home Galaxy appeared first on Sci.News: Breaking Science News.
Using spectral data from the Near-Infrared Spectrograph (NIRSpec) onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers analyzed the atmosphere of TOI-199b, a distant Saturn-mass world that is neither frozen nor scorching hot.
The post Webb Detects Methane in Atmosphere of Exo-Saturn TOI-199b appeared first on Sci.News: Breaking Science News.
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