Latest news with #AnneMarieLagrange
Yahoo
an hour ago
- Science
- Yahoo
James Webb telescope discovers its first planet — a Saturn-size 'shepherd' still glowing red hot from its formation
When you buy through links on our articles, Future and its syndication partners may earn a commission. The James Webb Space Telescope (JWST) has captured its first direct image of a planet in a remote solar system, and it's lighter than any seen before. The planet, named TWA 7b, is a gas giant with a size comparable to Saturn's. Orbiting a star just over 6 million years old, the planet is still glowing hot from its formation. The planet is the first observation of hypothesized yet previously unseen "shepherd" planets, which clear gaps of material found inside planetary rings. The researchers behind the discovery published their findings June 25 in the journal Nature. "It tells us that indeed, planets can form gaps in disks (which was theorised, but not observed) and trojan-like structures can indeed be present in exoplanetary systems," lead study author Anne-Marie Lagrange, an astronomer and research director at the French National Center for Scientific Research (CNRS) in Paris, told Live Science. "It is the first time that such a light planet is imaged, ten times lighter than the lightest [previously known] planet," she said. "This is thanks to the extreme sensitivity of JWST in the thermal domain." Astronomers study exoplanets because they help them to understand how planetary systems, such as our own, form. Yet while thousands have been seen indirectly — through the dimming of host stars as they pass in front of them or the wobble the planets' gravitational tugs give them — the light bouncing off exoplanets is usually drowned out by the light from the star, making them effectively invisible. Related: 'Eyeball' planet spied by James Webb telescope might be habitable To peer through this glare, JWST uses a coronagraph attached to its Mid-Infrared Instrument (MIRI); this device blocks out a star's light and makes it easier to spot objects orbiting around it. To further boost the effectiveness of this search, astronomers select young stars whose planetary disks are pole-on to the telescope, enabling them to 'look down' over star systems whose satellites are still glowing hot from their formation. RELATED STORIES —James Webb telescope spots wind blowing faster than a bullet on '2-faced planet' with eternal night —James Webb telescope discovers oldest black hole in the universe —James Webb telescope finds origins of the biggest explosion since the Big Bang — revealing a new cosmological mystery The system containing TWA 7b, called TWA 7, is 110 light-years from Earth and contains three concentric rings of rocky debris and dust, one of which was narrow and flanked by two empty bands of space. Within the heart of this narrow ring, the scientists found a hole containing a source of infrared-radiation. Follow-up simulations suggested that this radiation source is a planet roughly 30% the size of Jupiter that's orbiting its star at 52 times the distance that Earth orbits the sun. Its presence in a gap inside the planetary ring is also intriguing; while observations of holes in the discs surrounding stars have been made before in other systems, this is the first clear detection of the shepherd planets believed to create them. To further investigate the new system and others like it, Lagrange said that she and her colleagues will obtain "more data to study TWA7 b atmosphere, to search for other light, cold young planets in imaging" and "to search for cold old massive planets."
Gizmodo
13 hours ago
- Science
- Gizmodo
Webb Telescope Just Did Something It's Never Done Before—and Astronomers Are Thrilled
Since it began its science operations in July 2022, the James Webb Space Telescope has been probing the atmospheres of alien planets to study their potential for habitability. For the first time, however, Webb has discovered its own exoplanet, finding a young system hidden in a swirling cloud of dust and debris. Webb has captured a previously unseen exoplanet, the lightest planet imaged so far—an accomplishment made possible by the space-based telescope's advanced capabilities. The recent discovery, detailed in a paper published Wednesday in the journal Nature, marks Webb's first discovery of an exoplanet and opens up a new window into hidden, Saturn-like worlds. 'The planets are much fainter by orders of magnitudes than their parent stars, and seen from Earth or from JWST, they are angularly very close to them,' Anne-Marie Lagrange, research director at the French National Center for Scientific Research and lead author of the paper, told Gizmodo. 'Hence, when looking at a planet we see only the star.' In order to overcome this issue, the team behind the new discovery used a coronagraph—a telescopic attachment for Webb's Mid-Infrared Instrument. The coronagraph recreates the effect of a solar eclipse, blocking the light from a star to make its surroundings more visible. Using the coronagraph, the scientists spotted a young planetary system that's only a few million years old. The system, named TWA 7, has three distinct rings, one of which is especially narrow while being surrounded by two areas that hold almost no matter. In Webb's image, something lies within the heart of the narrow ring, which the scientists behind the study concluded is an exoplanet. The newly discovered exoplanet, dubbed TWA 7b, is more massive than Neptune but around 30% less massive than Jupiter, the largest planet of our solar system. TWA 7b, designated a sub-Jupiter, has a mass similar to that of Saturn's and orbits around a star that formed approximately 6.4 million years ago. The planet maintains a large distance of 52 astronomical units (in which 1 au is the average distance between the Earth and the Sun) from its star. 'It is also the first planet explaining gaps in a disk,' Lagrange said. 'It is unique to explain disk-planet interactions during the early phases of planetary systems.' Planets form from the material leftover from the birth of a star, which create a swirling disk of matter. Previous observations of these protoplanetary disks has revealed ring-like structures and gaps, which were believed to be signatures of unseen planets. So far, there were no direct observations of those planets. The mass and orbital features of TWA 7b, however, match the predicted properties of an exoplanet that may have formed in the gap between the first and second ring of the disk. By using Webb to observe young, faint planets, scientists have unlocked a new doorway into the discovery of alien worlds. 'In terms of imaging, it opens the possibility to image Saturn-like planets. In further steps, it will allow us to characterize the atmosphere of Saturn-like, non irradiated planets,' Lagrange said. 'It is a big step. It helps us knowing what is complicated when searching for very light planets.'
The Guardian
13 hours ago
- Science
- The Guardian
James Webb telescope captures the first direct images of an exoplanet
The James Webb space telescope has captured unprecedented direct images of a planet beyond our own solar system in its first exoplanet discovery. The observations reveal a planet, called TWA 7 b, carving its way through a disc of glowing dust and rocky debris in orbit around a star 110m light years from Earth. About the mass of Saturn, the planet is10 times less massive than any previous exoplanet to be directly observed with a telescope and provides fresh insights into a planetary system in its infancy. Dr Anne-Marie Lagrange, an astrophysicist at the Paris Observatory who led the observations, said: 'Here we're looking at a system that is about 6m years old, so we are really witnessing the youth of the planetary system.' Since the first exoplanet was discovered in 1992, nearly 6,000 more have been discovered, but almost all of these have been identified through indirect methods such as spotting the planet's shadow passing across the face of their host star. Imaging exoplanets directly remains a huge challenge as they are far less bright than their host star and, as seen from Earth, located very close to their star. To overcome this, Lagrange and colleagues developed a telescopic attachment designed to reproduce the effect of an eclipse, masking the star to make it easier to observe surrounding objects that would otherwise be drowned out. This allowed them to observe the star TWA7 'pole on' – effectively looking down on its planetary disk from above. The images reveal three concentric rings of dust and debris around the star – structures that have previously been attributed to unseen 'shepherd' planets carving through the disk. In this case, the astronomers were able to make observations of a planet itself, which appears as a brighter source within a narrow ring. The planet is thought to be a gas giant, about the mass of Saturn, making it by far the smallest mass planet to be observed by direct imagery. Positioned about 50 times as far from its star as Earth is from the sun, TWA 7 b has an orbital period of several hundred years. The finding is reported in the journal Nature.
