BIG SUNSPOT: Sunspot AR2736, which hurled a CME toward Earth yesterday, is growing larger and crackling with C-class solar flares. The active region now sprawls across more than 100,000 km of the solar disk and contains multiple dark cores as large as Earth, making it one of the biggest sunspots in recent years. Visit Spaceweather.com to watch a movie of the growing spot and to find out what makes it so explosive.
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Above: Magnetic and white-light images of sunspot AR2736 from NASA's Solar Dynamics Observatory