Trappist-1 is a red dwarf star that hosts multiple planets.
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The James Webb Telescope (JWST) searched for an atmosphere on one of the well-known TRAPPIST-1 exoplanets, but found nothing. Some models predicted the presence of thick atmospheres on all these worlds, but the complete absence of atmospheres could reduce the number of potentially habitable planets in the universe.
The TRAPPIST-1 system consists of at least seven planet-orbiting red dwarf stars, four of which orbit in the habitable zone (the region around the star where temperatures allow liquid water). His Thomas Greene and his colleagues at NASA’s Ames Research Center in California used JWST to observe the closest planet to the star, TRAPPIST-1b.
They examined the planet just before and after it passed behind the star. This is the perfect time to learn how heat from stars affects planets. “People predicted that these planets would have fairly thick atmospheres that circulated heat around them, so they didn’t get very bright,” Greene says. “So we figured we’d have to stack them to see anything, so we made five observations, and when the data came back, it was staring us in the face.”
TRAPPIST-1b is much brighter than researchers expected, indicating that the Sun’s light hits one side of the planet and is not absorbed by its thick atmosphere. The temperature on that side of the Earth, called the dayside, was about 230°C (446°F), about 100°C higher than would be expected if there was an atmosphere that disperses heat across the globe.
The most likely explanation is that the planet’s atmosphere was lost shortly after it formed when the star was at its brightest, or that a powerful stellar flare removed it. “There’s a lot of energy being released onto the planet, which can have a negative impact on the atmosphere,” says Greene. “There are probably important interactions between stars and planets. It will be very interesting to see the results for the whole system.”
Over the next year, various groups of researchers will use JWST to observe worlds in TRAPPIST-1. They are so numerous that the system could serve as a laboratory to understand the exact conditions of various exoplanets around red dwarfs and whether they are suitable for life. space and is expected to host the majority of exoplanets.
topic:
- exoplanet/
- james webb space telescope
