Here's How James Webb Telescope Will Detect Exoplanets
Tech - News
One of the big highlights of the release of the first science data from the James Webb Space Telescope was the spectrum of an exoplanet atmosphere, showing how Webb's instruments can see what these distant atmospheres are made of. This is a massive leap forward in exoplanet research and could even help find potentially habitable worlds.
Planets may seem big, but in the galactic scheme of things, they are very tiny, which makes observing them extremely difficult; however, using the transit method, they can be spotted by looking at the star they orbit around, called their host star. When a planet passes in front of its host star, the observer will notice the amount of light from the star will drop very slightly.
The James Webb collects this data via its Near-Infrared Imager and Slitless Spectrograph (NIRISS) instrument, specifically its Single-Object Slitless Spectroscopy (SOSS) mode. This mode can study exoplanets by de-focusing the very bright star, and spreading its light across pixels so that the effects of the relatively small planet can be observed.
The transit method is just one way of identifying and studying exoplanets. Webb will also work with ground-based telescopes to discover new exoplanets, and employ the radial velocity method to learn about exoplanets’ mass. It will even be able to directly image some exoplanets using a technique called coronagraphy.