NASA's James Webb Space Telescope (JWST) has once again revealed cosmic wonders beyond the human imagination. Following up on the work of the infrared Spitzer Space Telescope, JWST has discovered an Earth-like planet that emits light.
A Promising Exoplanetary System
In a star system called TRAPPIST-1, seven Earth-sized planets revolved around a cold star. With the help of JWST, astronomers explored the characteristics of TRAPPIST-1b, the planet closest to the host star.
TRAPPIST-1 is a star that is much smaller and cooler than our Sun. It is located approximately 40 light years away from Earth. Astronomers have been fascinated by it since 2017 when its Earth-sized exoplanets were discovered.
A team of researchers, including Ryan MacDonald, an astronomer from the University of Michigan and NASA Sagan Fellow, made an investigation centered around the information that can be obtained regarding the impact of the star on observations of the TRAPPIST-1 star system. Their findings are explained in the paper "Atmospheric Reconnaissance of TRAPPIST-1 b with JWST/NIRISS: Evidence for Strong Stellar Contamination in the Transmission Spectra."
The researchers did not see any sign of an atmosphere around TRAPPIST-1b. This means that the planet could be bare rock, with clouds high in the atmosphere, or have a very heavy molecule such as carbon dioxide that makes the atmosphere too small to detect.
The new data provides insights into how a star can affect observations of exoplanets in the habitable zone of cool stars. In this zone, liquid water can still exist on the surface of the orbiting planet.
Light From Extraterrestrial World
Another study was conducted by a group of experts led by Olivia Lim of the Trottier Institute for Research on Exoplanets at the University of Montreal. They used transmission spectroscopy to gain important insights into the properties of TRAPPIST-1b.
This method allowed them to analyze the light of the central star after passing through the exoplanet's atmosphere during transit. As a result, scientists can see the unique fingerprints left behind by the molecules and atoms found within that atmosphere.
The key finding of the study was the significant impact of stellar activity and contamination when trying to identify the nature of an exoplanet. Stellar contamination refers to the influence of the star's features on the measurements of the exoplanet's atmosphere.
Lim and her colleagues found evidence that stellar contamination plays an important role in shaping the transmission spectra of TRAPPIST-1b and likely the other planets in the star system. This finding underscores the importance of considering stellar contamination in planning for future observations of all exoplanetary systems.
The contamination was observed from stellar spots and faculae, as well as stellar flares, unpredictable events during which the star appears brighter for several minutes to hours. Such flares affected the experts' measurements of the amount of light blocked by the planet. Although these signatures of stellar activity are not easy to model, astronomers need to account for them to ensure that they interpret the data correctly.
RELATED ARTICLE : The Outermost Planet of TRAPPIST-1 is Observed in Detail; Based on Data from Keppler Telescope
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