Using a deformable mirror in “adaptive optics” at the Big Bear Solar Observatory in Big Bear City, California, the New Jersey Institute of Technology achieved this photograph of a sunspot using visible light. The image was published today as the photo of the day on the website of the popular astronomy magazine, Ciel et l’Espace.
The photo was announced by Distinguished Professor Philip R. Goode in NJIT’s press release, which contains the technical details of the photograph. The deformable mirror is designed to correct atmospheric distortion. The photograph’s resolution is 0.09 seconds of arc or 65 kilometers of the sun’s surface.
The center of the sunspot is the coolest region–about 3600° C. Around it is a mosaic of small cells, called granulation. The cells have a temperature of about 5800° C. They average about 1000 kilometers and are made of hot gas rising from inside the Sun.