“White sunspot” 27/07/2017

“SpaceWeather” (http://www.spaceweather.com/) says:

“WHITE SUNSPOT”: Sunspot numbers have dropped to zero this week as dark cores associated with sunspot activity have vanished. Instead of dark spots, the sun has a light spot.

The correct name of this phenomenon is “faculae.” It is a cousin of sunspots. 

Regular dark sunspots are magnetic islands on the surface of the sun. Magnetic fields in these areas are typically thousands of times stronger than Earth’s magnetic field. Sunspot magnetic fields are so strong, they block the flow of heat from the nuclear furnace below. They appear dark because they are relatively cool compared to their surroundings.

Faculae are also made of magnetic fields. However, the magnetism of faculae is concentrated in much smaller bundles than in sunspots. Instead of blocking heat from below, they essentially form corridors that allow us to see into sun’s hot interior, creating an apparent bright spot on the surface of the sun.

These bright structures are more common than you might think. During the peak of a sunspot cycle, faculae actually win out over sunspots and make the sun appear slightly (about 0.1%) brighter at Solar Maximum than at Sunspot Minimum.

I could see no sign of it on the SOHO web-site today, but it is visible in H-alpha. The spot is clear enough, but not much doing on the prominence front.

2 Responses

  1. I spent nearly hjalf an hour thinking that was a dust bunny or something because I couldn’t get rid of it from my scope view 🙂

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