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New Webb Telescope TRAPPIST-1 Image: Cool Star Is a Hot Topic
8 August 2022
EIRNS—The James Webb Space Telescope released data on July 18 of the red dwarf sun, TRAPPIST-1, and the data were subsequently rendered into images by citizen scientists. The Webb can study a star system with potentially habitable planets as no previous instrument has been able to do.
TRAPPIST-1 was discovered in 2017, and is a sun much cooler than our Sun—ours is about 5500 C, and TRAPPIST-1 is about 2300 C. It is only about 11% its diameter, making it slightly larger than the planet Jupiter. It has been a top priority for Webb, which began studying it almost as soon as it became capable of scientific observations. TRAPPIST-1 lies a mere 39 light years from Earth, in a part of our Milky Way galaxy which contains numerous red dwarf stars. It has a system of seven rocky exoplanets—planets that exist outside of the solar system—orbiting it with sizes and masses similar to that of Earth, and all of them orbit very close to the red dwarf. Three of them are considered to be in the “habitable zone”—the zone in a solar system in which water can exist in liquid form on the surface of a planet. Webb’s first task will be to detect if the three exoplanets even have an atmosphere, and next, will search for the presence of elements such as carbon dioxide, water vapor and ozone. Webb observed TRAPPIST-1 with its NIRISS (Near InfraRed Imager and Slitless Spectrograph) instrument. Since it can detect heavenly bodies in this range, it can distinguish more detail than the Hubble telescope. Webb is also in a more stable orbit than that of the Hubble telescope, orbiting the Sun at the L2 point of Earth’s orbit, and can remain on an observational target for hours at a time. The light coming from the original image is broken into the different individual wavelengths that make it up. Because each chemical element radiates and absorbs different wavelengths of light, scientists can use the spectrum of light from an object to understand what it’s made of—helium has a much different spectral signature (the lines of different colors that show up on a spectrograph) than hydrogen . As the light from TRAPPIST-1 passes by one of the planets, it will travel through any atmosphere, and then Webb will be able to view the spectrum of the elements. The molecules that are considered the precursors of life are called “bio-signatures.” An atmosphere can in turn be affected by the solar wind, tidal locking (where one side of a planet is always facing its sun), as well as geological and biological processes, which can cycle carbon, nitrogen and oxygen through the rocky planets’ atmospheres leading to different transformations depending upon oceans, plate tectonics and life itself. Newsweek quoted Michaël Gillon, an exoplanet researcher at the University of Liège in Belgium who led the team that discovered the TRAPPIST-1 system: “The question we will want to answer now is do they have an atmosphere? If they have an atmosphere, then things will become very exciting,” said Gillon. “Something worth noting is that something can be easily detectable just because it has very strong features, but it might be very, very low quantity,” remarked Julien de Wit, assistant professor in the Earth, Atmospheric and Planetary Sciences department at the Massachusetts Institute of Technology and part of the team that discovered the TRAPPIST-1 system. “So we will start finding molecular features, that’s great. But then the next step would be for us to have enough data so we can start discussing how much there is of this, of that, and then we can start even extracting information about the temperature, as a function of altitude, and pressure.” Astronomers and citizen scientists around the globe are eagerly awaiting what Webb might discover next , and what could be the next step in answering mankind’s oldest question, “Are we alone?” [jgw] |
