X

Vous n'êtes pas connecté

Maroc Maroc - EURASIAREVIEW.COM - A la une - 15/Jul 22:13

NASA’s Webb Investigates Eternal Sunrises, Sunsets On Distant World

Researchers using NASA’s James Webb Space Telescope have finally confirmed what models have previously predicted: An exoplanet has differences between its eternal morning and eternal evening atmosphere. WASP-39 b, a giant planet with a diameter 1.3 times greater than Jupiter, but similar mass to Saturn that orbits a star about 700 light-years away from Earth, is tidally locked to its parent star. This means it has a constant dayside and a constant nightside—one side of the planet is always exposed to its star, while the other is always shrouded in darkness. Using Webb’s NIRSpec (Near-Infrared Spectrograph), astronomers confirmed a temperature difference between the eternal morning and eternal evening on WASP-39 b, with the evening appearing hotter by roughly 300 Fahrenheit degrees (about 200 Celsius degrees). They also found evidence for different cloud cover, with the forever morning portion of the planet being likely cloudier than the evening. Astronomers analyzed the 2- to 5-micron transmission spectrum of WASP-39 b, a technique that studies the exoplanet’s terminator, the boundary that separates the planet’s dayside and nightside. A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves in front of the star, to the unfiltered starlight detected when the planet is beside the star. When making that comparison, researchers can get information about the temperature, composition, and other properties of the planet’s atmosphere. “WASP-39 b has become a sort of benchmark planet in studying the atmosphere of exoplanets with Webb,” said Néstor Espinoza, an exoplanet researcher at the Space Telescope Science Institute and lead author on the study. “It has an inflated, puffy atmosphere, so the signal coming from starlight filtered through the planet’s atmosphere is quite strong.” Previously published Webb spectra of WASP-39b’s atmosphere, which revealed the presence of carbon dioxide, sulfur dioxide, water vapor, and sodium, represent the entire day/night boundary – there was no detailed attempt to differentiate between one side and the other. Now, the new analysis builds two different spectra from the terminator region, essentially splitting the day/night boundary into two semicircles, one from the evening, and the other from the morning. Data reveals the evening as significantly hotter, a searing 1,450 degrees Fahrenheit (800 degrees Celsius), and the morning a relatively cooler 1,150 degrees Fahrenheit (600 degrees Celsius). “It’s really stunning that we are able to parse this small difference out, and it’s only possible due Webb’s sensitivity across near-infrared wavelengths and its extremely stable photometric sensors,” said Espinoza. “Any tiny movement in the instrument or with the observatory while collecting data would have severely limited our ability to make this detection. It must be extraordinarily precise, and Webb is just that.” Extensive modeling of the data obtained also allows researchers to investigate the structure of WASP-39 b’s atmosphere, the cloud cover, and why the evening is hotter. While future work by the team will study how the cloud cover may affect temperature, and vice versa, astronomers confirmed gas circulation around the planet as the main culprit of the temperature difference on WASP-39 b. On a highly irradiated exoplanet like WASP-39 b that orbits relatively close to its star, researchers generally expect the gas to be moving as the planet rotates around its star: Hotter gas from the dayside should move through the evening to the nightside via a powerful equatorial jet stream. Since the temperature difference is so extreme, the air pressure difference would also be significant, which in turn would cause high wind speeds. Using General Circulation Models, 3-dimensional models similar to the ones used to predict weather patterns on Earth, researchers found that on WASP-39 b the prevailing winds are likely moving from the night side across the morning terminator, around the dayside, across the evening terminator and then around the nightside. As a result, the morning side of the terminator is cooler than the evening side. In other words, the morning side gets slammed with winds of air that have been cooled on the nightside, while the evening is hit by winds of air heated on the dayside. Research suggests the wind speeds on WASP-39 b can reach thousands of miles an hour! “This analysis is also particularly interesting because you’re getting 3D information on the planet that you weren’t getting before,” added Espinoza. “Because we can tell that the evening edge is hotter, that means it’s a little puffier. So, theoretically, there is a small swell at the terminator approaching the nightside of the planet.” The team’s results have been published in Nature. The researchers will now look to use the same method of analysis to study atmospheric differences of other tidally locked hot Jupiters, as part of  Webb Cycle 2 General Observers Program 3969. WASP-39 b was among the first targets analyzed by Webb as it began regular science operations in 2022. The data in this study was collected under Early Release Science program 1366, designed to help scientists quickly learn how to use the telescope’s instruments and realize its full science potential.

Articles similaires

Why are scientists proposing to warm up Mars, how will they do it?

times of india - 10/Aug 02:39

Scientists proposed to introduce engineered nanoparticles into Mars' atmosphere to raise its temperature by 50 degrees Fahrenheit over ten years....

Scientists have found a revolutionary way to warm Mars, but at what cost?

vaughantoday.ca - 11/Aug 03:09

On Mars, it’s too cold for liquid water to flow on the surface. But researchers have an idea that could change that. One that could raise the...

Sorry! Image not available at this time

7 Best Trucker Jackets for Men: Vintage Versatility in 2024

fashionbeans.com - 08/Aug 07:38

Picture this: it’s the first true evening of autumn. Maybe not officially, but the first night that really feels like the summer is over. The...

Sorry! Image not available at this time

The Role Of The Holy Spirit: Distinguishing Between Your Will And God’s Will

dailywire.com - 16/Aug 11:43

The following is a transcript excerpt from Dr. Jordan Peterson’s conversation with country music artist John Rich on prayer, how to discern the...

Loftus-Cheek says Milan are ‘optimistic’ and praises the fans: “Perfect atmosphere”

sempremilan.com - 17/Aug 18:26

By: Isak Möller Ahead of the game between Milan and Torino this evening, Ruben Loftus-Cheek spoke to the club’s official channel and shared his...

🎥‍🚀🌌 (Party Pooper Cooper Cons and Pros) From illuminati icon Schwarzenegger to Oscar-winning McConaughey ~ Aug 10, 2024 ~ |

verdensalt.dk - 10/Aug 10:08

The Final Frontier: Cooper faces his greatest challenge yet - healing Earth hours from dying (close to extinction)...... SoTW almost cried to the...

Sorry! Image not available at this time

‘Secret Level’: Tim Miller to Direct a Unique Animated Video Game Series!!

movizark.com  - 15/Aug 17:28

The director of the first Deadpool movie and a divisive entry in the Terminator franchise has signed on for his next project. A new report from...

Sorry! Image not available at this time

Today’s weather: Another hot sunny day

cyprus-mail.com - 09/Aug 05:01

Once the early morning mist, fog, and low cloud have cleared, Friday will be another warm and sunny summer’s day for the most part. Temperatures...

Golden Hands tops ensemble category at National Steelband Music Festival

newsday.co.tt - 10/Aug 05:22

GOLDEN Hands has surged to the forefront of the Ensemble category of the Trinidad and Tobago National Steelband Music Festival, despite the death of...

Hope Fades For Sokoto Farmers As Perennial Flooding Destroys Farmlands

humangle.ng - 10/Aug 08:00

The unusual roars of the cloudy sky over the village of Tsitse chiselled a warm smile on Salihu Yakubu’s face. For months, the land had grappled...