Flare Alert: Monster Sunspot Turns Toward Earth

Discovery.com

Just as the US prepares to watch the partial solar eclipse today, nearly 100 million miles away on the sun a possible solar storm is brewing.

Amateur astronomers have been wowed by a vast sunspot that has rotated to face Earth, the largest since this solar cycle began in 2008, and solar observatories (on the ground and orbiting Earth) are closely monitoring the region.

PHOTOS: Simmering Solar Views from SDO

The sunspot, a dark patch in the sun’s photosphere, represents intense solar magnetism bursting from the sun’s interior known as an active region. This particular active region, designated AR2192, has been rumbling with intense flare activity, recently exploding with 2 X-class flares, causing some short-lived high-frequency (HF) radio black outs around the globe.

Such blackouts are triggered by the intense extreme ultraviolet and X-ray radiation that solar flares can generate, causing ionization effects in the Earth’s upper atmosphere — a region known as the ionosphere. HF radio can be strongly hindered by this activity, triggering blackouts that can effect air traffic and amateur radio operators.

Currently, the sunspot located at the base of AR2192 has swelled to over 80,000 miles across — Jupiter could almost fit inside the sunspot’s mottled diameter.

PHOTOS: The Psychedelic Anatomy of a Solar Flare

While making for a spectacular astronomy target, especially as it coincides with today’s partial solar eclipse, space weather forecasters are trying to gauge whether the active region could explode with more powerful solar flares.

Since the start of this week, AR2192 has generated 27 C-class flares, 8 M-class flares and 2 X-class flares. Most recently, on Oct. 22 (Wednesday), an X1.6 flare erupted, creating an extremely bright eruption in the sun’s lower corona (the solar atmosphere) that was captured by NASA’s Solar Dynamics Observatory (SDO):