Seven rocky planets orbit the nearby dwarf star TRAPPIST-1, providing a unique opportunity to search for atmospheres on small planets outside the Solar System. Thanks to the recent launch of the NASA/ESA/CSA James Webb Space Telescope, possible atmospheric constituents such as carbon dioxide are now detectable. In the new research, astronomers used the new data from Webb’s Mid-Infrared Instrument (MIRI) to calculate the amount of heat energy coming from the rocky exoplanet TRAPPIST-1c.
TRAPPIST-1 is an ultracool M-dwarf star located 38.8 light-years away in the constellation of Aquarius.
Also known as K2-112 or TIC 278892590, the star is barely larger than Jupiter and has just 8% of our Sun’s mass.
In February 2017, astronomers announced that the star hosts at least seven planets: TRAPPIST-1b, c, d, e, f, g and h.
All these planets are similar in size to Earth and Venus, or slightly smaller, and have very short orbital periods: 1.51, 2.42, 4.04, 6.06, 9.21, 12.35 and 20 days, respectively.
Three of these planets, TRAPPIST-1b, c and d, lay in the star’s habitable zone, meaning they may harbor suitable conditions for life.
“We want to know if rocky planets have atmospheres or not,” said Sebastian Zieba, a graduate student at the Max Planck Institute for Astronomy.
“In the past, we could only really study planets with thick, hydrogen-rich atmospheres.”
“With Webb we can finally start to search for atmospheres dominated by oxygen, nitrogen, and carbon dioxide.”
“TRAPPIST-1c is interesting because it’s basically a Venus twin,” said Dr. Laura Kreidberg, also from the Max Planck Institute for Astronomy.
“It’s about the same size as Venus and receives a similar amount of radiation from its host star as Venus gets from the Sun.”
“We thought it could have a thick carbon dioxide atmosphere like Venus.”
In their study, the astronomers used Webb’s MIRI instrument to observe the TRAPPIST-1 system on four separate occasions as the planet…
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