The largest solar telescope on Earth has had the sharpest view of a sunspot.
Vaguely like a sunflower, or the Eye of Sauron from The Lord of the Rings, the stain appears as a dark stain surrounded by ribbons of plasma that have been sculpted by magnetic fields gushing from the center of the stain. At roughly 15,000 kilometers in diameter, the entire place could comfortably gobble up the Earth with room to spare.
The image was captured last January by the new Daniel K. Inouye Solar Telescope on Maui in Hawaii, observatory director Thomas Rimmele and colleagues report in the December 4 journal Solar Physics. With its 4-meter wide mirror, the telescope is beginning to provide the highest resolution views of our star to date (SN: 1/29/20). The ability to see details as small as 20 kilometers in diameter can help researchers get to the root of enduring mysteries about the sun (SN: 8/21/20), such as why its outer atmosphere is millions of degrees warmer. hot than its surface.
Sunspots mark where beams of magnetic fields pass through the sun’s surface. Magnetic fields suppress hot gas bubbling from below, cooling the surface and making it appear darker than its surroundings. While the average surface temperature is about 5,500 ° Celsius, the core of a sunspot could be “only” 3,700 ° C.
The image was taken as part of a test for the nearly completed telescope, which should open sometime in 2021. While the observatory is targeting late spring or early summer, says Claire Raftery, director of communications for the National Solar Observatory In Boulder, Colorado, the ongoing COVID-19 pandemic may delay opening.