SWAP (instrument)

The Sun Watcher using Active Pixel System Detector and Image Processing telescope is a compact extreme-ultraviolet imager on board the PROBA-2 mission. SWAP provides images of the solar corona at a temperature of roughly 1 million degrees. the instrument was built upon the heritage of the Extreme ultraviolet Imaging Telescope which monitored the solar corona from the Solar and Heliospheric Observatory from 1996 until after the launch of the Solar Dynamics Observatory in 2010.
SWAP's coronal mass ejection watch program has collected images at an improved image cadence since the PROBA-2 launch in 2009. These events include EIT waves, EUV dimming regions, filament instabilities. SWAP's EUV images of the corona routinely extend beyond 2 solar radii from the surface of the Sun, much further than was thought possible before the mission was launched. This led to the discovery, in 2021 by Seaton et al. using the SUVI instrument on board NOAA's GOES satellite, that the extended solar corona is visible in the extreme-ultraviolet, out to at least 3 solar radii from the center of the Sun.
SWAP was built at the Liège Space Center and is operated from the PROBA-2 Science Center at the Royal Observatory of Belgium.
SWAP has been used to study coronal brightspot dynamics.