Opportunity to Observe on 20/21 Dec Sunset/Sunrise time only - Dont use binocular/telescope:
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. A sunspot is approximately 1500 degrees Celsius cooler than it's surrounding material. The number of sunspots we see on the Sun at any given time appears to cycle every 11 years.
How Big are they ?
Sunspots expand and contract as they move across the surface of the Sun with a size ranging from 16 kilometers 10 mi to 160,000 kilometers in diameter. The larger variety are visible from Earth without the aid of a telescope..
Story behind the picture :
It is interesting to note one such huge Sunspot was captured (for Indian Express on 19 Dec.) by Photo Journalist Mr.Koteshwar Rao when he observed something strange on Sun and contacted PSI.
When contacted Director and founder Secretary Mr.N.Sri Raghunandan Kumar the image was verified using NASA Solar Dynamic Observatory (SDO) &HMI DATA (15Dec to 19 Dec) and Confirmed it to be Sunspot which is designated as AR2470.
Sunspot AR 2470 can be observed across the world on 20Dec when Sun is setting in the evening near horizon or when Sun is rising in the morning on 21 Dec. However we do not suggest staring at Sun when it quiet high in the sky.