Where Have All The Sunspots Gone?

Gone to solar minima everyone
This view from SOHO on 12/26/07 shows a blank solar disk. Cool. Not completely unusual, just mostly. There was the Maunder Minimum, of course.

The possible absence of sunspots for some 70 years in the 17th century was first pointed out by the Spörer (1887) using the extensive compilation of data by Wolf (1856, 1868). Spörer’s work was summarized by Maunder (1890, 1894), who commented, following Clerke (1894), that this dearth of sunspots apparently coincided with an absence of terrestrial aurorae. We now know that aurorae are caused by sub-atomic particles emitted by the Sun during releases of magnetic energy which often accompany sunspots. To supplement Spörer’s use of Wolf’s data, Maunder quotes the editor of Philosophical Transactions describing the observation of a sunspot in 1671 by Cassini in Paris with the comment that it was the first seen for many years. Much later, Maunder (1922) found a note by Flamsteed, the first Astronomer Royal, describing a sunspot seen at Greenwich in 1684, in which Flamsteed says that it is the first he had seen since 1674. Flamsteed made several other references to this spot and to his solar observations in general in his correspondence, the definitive edition of which is now nearing completion (Flamsteed 1995). Maunder also took evidence from Herschel (1801), who had referred to Lalande’s (1792) L’Astronomie in which detailed evidence relating to the absence of sunspots in the latter part of the 17th, and early 18th century was cited.

This mpeg of the solar disk for the last two weeks shows that there is one or two good sized groups on the “other side” of the sun.

Hey! Is that the dark side? The one that comes out at night???

Ohhhh – I’ll stop. I’ll be enjoying a few days off, and back with news from the intersection of religion and science (with some personal stuff thrown in for fun) before you know it.

Explore posts in the same categories: Astronomy

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