Credit: dailymail.co.uk

Like the centre of a flower or a mysterious eye, this is the most detailed image of a sunspot ever captured using visible light. The stunning picture was taken using the Big Bear Telescope in California and is the best photo of a huge sunspot that is around 13,000km in diameter.

At the centre of the sunspot the temperature is around 3,600C, while the surrounding regions are much hotter, more than 5,800C. The irregular shapes that surround the sunspot are known as granulation and are made of hot gas rising from inside the Sun. Each one is around 1000km in size.

The telescope that took the picture is know as the New Solar Telescope which uses adaptive optics, parts that change to adapt to disturbances in the atmosphere and correct distortions in the signals. Scientists believe magnetic structures, like sunspots, hold an important key to understanding space weather. Space weather, which originates in the Sun, can have dire consequences on Earth's climate and environment.

The telescope has a resolution covering about 50 miles on the Sun's surface. The Big Bear Observatory is located in a clear mountain lake which is known for its atmospheric stability. The images were taken by the NST with atmospheric distortion corrected by its 97 actuator deformable mirror.

The NST will be the pathfinder for an even larger ground-based telescope, the Advanced Technology Solar Telescope (ATST), to be built over the next decade. 

Recently, technicians at NASA's Marshall Space Flight Center in Huntsville, Ala., completed a series of cryogenic tests on six James Webb Space Telescope beryllium mirror segments at the center's X-ray & Cryogenic Facility. During testing, the mirrors were subjected to extreme temperatures dipping to -415 degrees Fahrenheit, permitting engineers to measure in extreme detail how the shape of the mirror changes as it cools.

The Webb telescope has 18 mirrors, each of which will be tested twice in the Center's X-ray & Cryogenic Facility to ensure that the mirror will maintain its shape in a space environment -- once with bare polished beryllium and then again after a thin coating of gold is applied.

The cryogenic test gauges how each mirror changes temperature and shape over a range of operational temperatures in space. This helps predict how well the telescope will image infrared sources.

The mirrors are designed to stay cold to allow scientists to observe the infrared light they reflect using a telescope and instruments optimized to detect this light. Warm objects give off infrared light, or heat. If the Webb telescope mirror is too warm, the faint infrared light from distant galaxies may be lost in the infrared glow of the mirror itself. Thus, the Webb telescope's mirrors need to operate in a deep cold or cryogenic state, at around -379 degree Fahrenheit.