The Near-Infrared Imager and Slitless Spectrograph instrument (NIRISS ), one of the four main scientific instruments of the James Webb Space Telescope, has finished its post-launch preparations and is now ready for research. Before the instrument was deemed prepared to start scientific operations, the Single Object Slitless Spectroscopy (SOSS) capability was the last NIRISS mode to be ticked off the list.
A customised prism assembly at the centre of the SOSS mode scatters a cosmic source’s light into three separate spectra (rainbows), exhibiting the shades of more than 2,000 infrared colours that were concurrently captured in a single observation. This mode will be used primarily to investigate the atmospheres of transiting exoplanets, or planets that sometimes eclipse their star, temporarily reducing the star’s brightness.
“I’m overjoyed and ecstatic to think that after a two-decade journey, Canada’s contribution to the mission has finally come to a close. Not only are all four NIRISS modes operational, but the instrument is outperforming our expectations in every way. The realisation that science operations will soon begin, and in particular that will soon begin probing the atmospheres of its first exoplanets, has me pinching myself “René Doyon, the University of Montreal’s main investigator for NIRISS and Webb’s Fine Guidance Sensor, stated.