New research by astronomers at the University of Washington uses the fascinating TRAPPIST-1 planetary system as a kind of laboratory to model not the planets themselves, but how the upcoming James Webb Space Telescope could detect and investigate their on-track atmospheres Search for life beyond the earth.
The study, led by Jacob Lustig-Yaeger, a graduate student in astronomy at UW, revealed that the James Webb telescope, due to launch in 2021, may even provide important information about the atmospheres of TRAPPIST-1 worlds can get in its first year of operation, unless, as an old song says, cloud clouds.
"The Webb telescope was built, and we have an idea of how it will work," Lustig-Yaeger said. "Using computer models, we have identified the most efficient way for the telescope to answer the most basic question we want to ask ourselves: are there any atmospheres on this planet or not?" The detectability and characterization of the TRAPPIST-1 exoplanet atmosphere with JWST was published online in June in the Astronomical Journal (19459014). The TRAPPIST-1 system, 39 light-years or about 235 billion miles – Outside of the constellation Aquarius, astronomers are interested in its seven orbiting rocky or earth-like planets. Three of these worlds are located in the star's habitable zone – that space strip around a star, which is just the thing to bring liquid water to the surface of a rocky planet and give life a chance.
The star, TRAPPIST-1, was much hotter in its formation than it was today, exposing all seven planets to ocean, ice and atmospheric losses in the past.
"There is a big question in the field of whether these planets have any atmospheres, especially the innermost planets," Lustig-Yaeger said. "Once we confirm that there are atmospheres, what can we learn about the atmosphere of each planet – the molecules that make it up?" Pretty short time, this paper finds.
Astronomers discover exoplanets as they pass or "pass" in front of their host star, causing a measurable darkening of the starlight. Planets that approach their star transit more often are a little easier to study. As a planet passes through its star, part of the star's light passes through the planet's atmosphere, allowing astronomers to experience the molecular composition of the atmosphere.
Funny-Yaeger said astronomers might notice tiny differences in the size of the planet see in different colors or wavelengths of light.
"This happens because the gases in the planet's atmosphere absorb light only in very specific colors. Since each gas has a unique & # 39; spectral fingerprint, we can identify it and begin setting the composition of the atmosphere
Lustig-Yaeger said the team's modeling suggested that the James Webb telescope could capture the atmosphere of all seven TRAPPIST-1 planets with a versatile onboard tool, the near-infrared spectrograph in 10 or less passes – if they have cloud-free atmospheres. And of course we do not know if they have clouds or not.
If the TRAPPIST-1 planets have thick, globally enveloping clouds, as Venus does, recognizing atmospheres can take up to 30 transits.
"But that's still an achievable goal," he said. "This means that the James Webb telescope will still be able to detect the presence of atmospheres – even in realistic clouds at high altitudes – which was not known before our release."
Lately many rocky exoplanets have been discovered for years, but astronomers have not yet discovered their atmospheres. The modeling in this study, Lustig-Yaeger said, "shows that for this TRAPPIST-1 system, the detection of terrestrial exoplanetary atmospheres with the James Webb Space Telescope is on the horizon – perhaps even as part of its primary five-year mission."  The team found that the Webb telescope may detect signs that the TRAPPIST-1 planets have lost large amounts of water in the past when the star was much hotter. This could leave behind cases in which abiotic-generated oxygen – which is not representative of life – fills an exoplanetic atmosphere that could give a kind of "false positive" to life. If this is the case with TRAPPIST 1 planets, the Webb telescope may also detect them.
Lustig-Yaeger's co-authors, both with the UW, are astronomy professor Victoria Meadows, who is also the principal investigator of the UW-based Virtual Planetary Laboratory; and astronomy graduate student Andrew Lincowski. The work is based in part on earlier works by Lincowski to model the possible climate for the seven TRAPPIST-1 worlds.
"In this study, we investigated: What are the best scenarios for the James Webb Space Telescope?" What can it do? Because there will definitely be more Earth-sized planets before it starts in 2021. "
The research was funded by a grant from the Virtual Planetary Laboratory team of the NASA Astrobiology Program as part of the Nexus for Exoplanet System Science (NExSS) Research Coordination Network.
Lustig-Yaeger added, "It's hard to imagine theoretically a planetary system better suited to James Webb than TRAPPIST-1."
Study brings new climate models of the seven fascinating worlds of the little star TRAPPIST 1
Jacob Lustig-Yaeger et al. The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmosphere with JWST, The Astronomical Journal (2019). DOI: 10.3847 / 1538-3881 / ab21e0
James Webb Space Telescope could begin to familiarize themselves with TRAPPIST 1 atmospheres in a single year, according to a study (2019, 14 August).
retrieved on August 14, 2019
This document is subject to copyright. Apart from any fair dealings for the purposes of private study or research, no
Part may be reproduced without written permission. The content is provided for informational purposes only.