This image of a sunspot, located in in NOAA AR 12227, was captured in December 2014 by the 0.5-meter Solar Optical Telescope on board the Hinode spacecraft. This image was processed by a team of scientists led by Rahul Yadav (Udaipur Solar Observatory, Physical Research Laboratory Dewali, India) in order to examine the properties of umbral dots: transient, bright features observed in the umbral region (the central, darkest part) of a sunspot. By exploring these dots, Yadav and collaborators learned how their properties relate to the large-scale properties of the sunspots in which they form — for instance, how do the number, intensities, or filling factors of dots relate to the size of a sunspot’s umbra? To find out more about the authors’ results, check out the article below.
Sunspot in NOAA AR 11921. Left: umbral–penumbral boundary. Center: the isolated umbra from the sunspot. Right: The umbra with locations of umbral dots indicated by yellow plus signs. [Adapted from Yadav et al. 2018]
Citation
Rahul Yadav et al 2018 ApJ 855 8. doi:10.3847/1538-4357/aaaeba