Phys.org July 20, 2021
Unlike coronal mass ejections which typically show up clearly on the Sun as dimming or brightening, the ‘stealth CMEs’ often originate at higher altitudes in the Sun’s corona, in regions with weaker magnetic fields and they are usually only visible on coronagraphs designed to reveal the corona. An international team of researchers (USA – UC Berkeley, industry, University of Maryland, NASA, Belgium, Romania, UK, India, Russia) has shown that many stealth CMEs can be detected in time if current analysis methods for remote sensing are adapted. They compared remote sensing images of the Sun with the same image taken between eight and 12 hours earlier, to capture very slow changes in the lower corona, up to 350,000km from the Sun’s surface. Comparing the images revealed changes in the loops of magnetic fields and plasma that are hurled from the Sun. Using another set of imaging techniques to further analyze the stealth CME’s approximate origin, they could predict whether it is headed towards Earth. With the new imaging techniques, they revealed previously undetected, tiny dimming and brightening on the Sun at the region of origin of four previous stealth CMEs. According to the researchers the technique can be used for early detection of risky stealth CMEs…read more. Open Access TECHNICAL ARTICLEÂ
…Intensity of extreme UV (EUV; 21.1 nm) captured by the Atmospheric Imaging Assembly instrument on board NASA’s Solar Dynamics Observatory…Credit: Palmerio, Nitta, Mulligan et al