Linktipp #50: 1000 Jahre Sonnenaktivität

Sagenhaft, schon Mitte Februar und noch kein einziger Blogpost in diesem Jahr! Verschiedene Arbeiten haben mir in den letzten Wochen kaum Zeit gelassen, spezifischen Blog-Content zu erstellen, dazu vielleicht in Kürze mehr an dieser Stelle. Damit die Wartezeit nicht zu lang wird, hier erst einmal ein Linktipp, erschienen diese Woche auf Sky&Telescope!

Visible-light images from NASA’s Solar Dynamics Observatory highlight the difference in sunspots at minimum (left) and maximum (right). NASA
Visible-light images from NASA’s Solar Dynamics Observatory highlight the difference in sunspots at minimum (left) and maximum (right).
NASA

Our Sun is not the faithfully constant light source it appears to be. Solar activity varies in a fairly regular cycle of 11 years, most notably in the periodic rise and fall in the number of sunspots. Though German astronomer Samuel Heinrich Schwabe discovered the cycle in the 19th century, sunspot observations commenced about 400 years ago with Galileo Galilei, and the solar cycle has been traced back to these early observations.

Now, a team of scientists based in Switzerland has successfully reconstructed the 11-year Schwabe cycle all the way back to the year AD 969, using the Sun’s imprint on ancient trees on Earth. Their report appears in Nature Geoscience. Weiter auf skyandtelescope.org!