Featured Image: Tracking a Hole from the Sun


The dramatic image above reveals the expansion of a large coronal cavity as it erupts from the Sun’s surface in the form of a coronal mass ejection. This is a combination of LASCO (background) and SWAP (overlay) observations; click to see the larger field, which spans 3 x 5 solar radii (the white quarter-circle marks one solar radius). To better understand what triggers powerful solar ejections, a team of scientists led by Ranadeep Sarkar (Udaipur Solar Observatory, India) has pieced together observations over time of a coronal cavity that was witnessed in 2010. This low-density cavity formed above the Sun’s surface and hung peacefully in the lower corona for nearly two weeks before erupting violently in a surge of plasma and radiation.

coronal cavity

This image of the cavity was taken with SDO nearly two weeks before the LASCO/SWAP image above. Here, the cavity is much smaller and sits in the lower corona above a prominence. [Adapted from Sarkar et al. 2019]

Sarkar and collaborators used observations from multiple vantage points — from the SDO, STEREO, SWAP, and LASCO observatories — to track the cavity’s evolution from a quiet bubble in the lower corona (see image to the right) to eruption into space. To see more images of the cavity and find out more about what the authors learned, check out the article below.


“Evolution of the Coronal Cavity From the Quiescent to Eruptive Phase Associated with Coronal Mass Ejection,” Ranadeep Sarkar et al 2019 ApJ 875 101. doi:10.3847/1538-4357/ab11c5