Sunspots and Solar Flares
The lifespan of a typical sunspot is two to three weeks. AR1990 is about to turn three Months. Carried around by the sun's 27-day rotation, AR1990 is making its third transit of the visible solar disk. In previous apparitions it was known as AR1944 and AR1967.
Each time it has appeared, the sunspot has unleashed at least one strong flare, the most recent being the X4.9-class blockbuster of Feb. 25th. Since then, AR1990 has quieted and started showing signs of decay.
Is this sunspot finally succumbing to time? The dimensions of the sunspot make it an easy target for relatively small optics. Its dark core is about the size of Earth, and it is surrounded by boiling granules as large as the state of Texas.
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