The Near-Infrared Imager and Slitless Spectrograph instrument (NIRISS), one of the James Webb Space Telescope’s four primary scientific instruments, has completed its post-launch preparations and is now ready for science.
The Single Object Slitless Spectroscopy (SOSS) capability was the last NIRISS mode to be checked off before the instrument was declared ready to begin scientific operations. A specialized prism assembly at the heart of the SOSS mode disperses the light of a cosmic source to create three distinct spectra (rainbows), revealing the hues of over 2,000 infrared colors collected simultaneously in a single observation. This mode will be used to investigate the atmospheres of transiting exoplanets, which are planets that periodically eclipse their star, temporarily dimming its brightness. By precisely comparing the spectra collected during and before or after a transit event, one can determine not only whether or not the exoplanet has an atmosphere, but also what atoms and molecules are present.
“I’m overjoyed and overjoyed to think that we’ve finally arrived at the end of Canada’s two-decade-long contribution to the mission. Not only are all four NIRISS modes operational, but the instrument as a whole is performing significantly better than expected. I’m pinching myself because we’re only a few days away from the start of science operations, and especially from NIRISS probing its first exoplanet atmospheres “René Doyon, principal investigator at the University of Montreal for NIRISS as well as Webb’s Fine Guidance Sensor.
After completing NIRISS post-launch commissioning activities, the Webb team will concentrate on testing the remaining five modes on its other instruments. On July 12, 2022, NASA’s James Webb Space Telescope, a collaboration with ESA and CSA, will release its first full-color images and spectroscopic data.