The largest solar telescope on earth has got the sharpest view of a sunspot.
As vague as a sunflower – or the eye of Sauron Lord of the Rings – The stain appears as a dark blemish encircled by plasma ribbons formed by magnetic fields that sprout from the center of the stain. With a diameter of roughly 15,000 kilometers, the entire place could comfortably devour the earth with space.
The picture was taken last January by the new Daniel K. Inouye solar telescope on Maui, Hawaii, reported observatory director Thomas Rimmele and colleagues on December 4th Solar physics. With its 4 meter wide mirror, the telescope offers the highest resolution of our star ever (SN: 01/29/20). The ability to see details as small as 20 kilometers in diameter can help researchers unearth the root of enduring mysteries about the sun (SN: 08/21/20), for example why its outer atmosphere is millions of degrees hotter than its surface.
Mark sunspots where bundles of magnetic fields strike through the sun’s surface. The magnetic fields suppress the inflation of hot gas from below, which cools the surface and makes it appear darker than its surroundings. While the average surface temperature is around 5,500 ° Celsius, the core of a sunspot can be “only” 3,700 ° C.
The picture was taken as part of a test run for the almost finished telescope, which is scheduled to go into operation sometime in 2021. With the observatory heading for late spring or early summer, Claire Raftery, communications director at the National Solar Observatory in Boulder, Colorado, says the ongoing COVID-19 pandemic may delay opening.