2021年06月の太陽

WHY ISN'T THIS SUNSPOT FLARING? Sunspot AR2835 is big, new, and just experienced a significant growth spurt. So why isn't it flaring? The answer lies in this magnetic map from NASA's Solar Dynamics Observatory:
Like all sunspots, AR2835 has a north pole ("+") and a south pole ("-"). The expanse between the two poles explains the quiet. In AR2835, there is very little mixing of green and yellow; that is, the magnetic polarities are cleanly separated. Solar flares tend to occur in sunspots where "+" and "-" bump together in many places, resulting in magnetic reconnection. AR2835 isn't like that. Until this changes, the forecast calls for quiet. Solar flare alerts: SMS Text.

ELLERMAN BOMBS: Bombs are going off around sunspot AR2835. Ellerman Bombs. Philippe Tosi photographed dozens of them yesterday from his backyard observatory in Nimes, France. Click on the image below to see the entire sunspot; a handful of the bomb-blasts are circled:

Ellerman bombs are magnetic explosions about one-millionth as powerful as true solar flares. They are named after physicist Ferdinand Ellerman who studied the tiny blasts in the early 20th century. Of course, "tiny" is relative. A single Ellerman bomb releases about 1026 ergs of energy--equal to about 100,000 World War II atomic bombs.
Why are these explosions happening? This magnetic map of AR2835 provides the answer:

Blue/green is magnetic north (+). Red/yellow is magnetic south (-). Credit: NASA/SDO
Note the ragged mixture of yellow and green around the periphery of the sunspot's primary core. These are magnetic fields of opposite polarity bumping together. Such a mixture is explosive. Ellerman bombs mark the points where magnetic reconnection is taking place. If this mixing continues, we could see a real solar flare soon. Stay tuned. Solar flare alerts: SMS Text.