Giant spots observed on Sun’s surface; ‘rare occurrence to continue for another 10 days,’ says Nehru Planetarium director

“Sunspots can unleash powerful X-class flares. These are also responsible for what is called a Coronal Mass Ejection (CME), when they spew out electrically charged particles, which can cause beautiful auroras near the northern and southern polar regions,” he said.

Paranjpye stated that the temperature of a sunspot is about 4,000 degree Celsius, whereas the temperature of the photosphere is about 6,300 degree Celsius. Sunspots appear dark because they are relatively cooler regions on the Sun, which itself is “about 108 times the size of the Earth,” he said.

He went on to add that on taking a closer look at a sunspot, a dark central region is revealed, called the umbra, as well as a less-dark region that surrounds it, called the penumbra. If the area surrounding the sunspot is blocked and only the umbra or penumbra is seen, then they appear red or orange in colour, respectively.

In the picture of the sunspot, taken by the Solar Dynamic Observatory of the US-based National Aeronautics and Space Administration (Nasa), one can clearly see the umbra and penumbra of the sunspots, he said.

For those interested in observing sunspots, Paranjpye advised that they should never look at the Sun with naked eyes, but they can, instead, use welder’s glasses of number 14 or higher grade. The best way to observe sunspots is to project an image of the Sun using a telescope. One can also use eclipse goggles, he added.