Under A Sunspot
8.11.2001

At the Sun's surface, sunspots are known to be dark, planet-sized regions of intense magnetic fields. But what lies below? Using observations from the Michelson Doppler Imager (MDI) instrument aboard the space-based SOHO observatory, astronomers have derived this premier picture of the flow of material just beneath a visible sunspot.

Sunspot Region 30
18.07.2002

The solar active region designated number 0030 is now appearing on the visible hemisphere of the closest star. Dwarfed by the Sun's disk, the group of sunspots which make up region 30 actually cover an enormous area -- nearly 10 times the size of Earth.

Solar Flares Cause Sun Quakes
1.06.1998

An 11th magnitude quake has been recorded on the Sun, immediately following a moderate solar flare. The quake was the first ever recorded on the Sun, but only because astronomers have only recently figured out when and how to find them using the orbiting SOHO spacecraft.

Follow The Spots
21.10.1999

The Sun rotates on its axis about once every 27 days. How can you tell? Just follow the sunspots. This composite picture was constructed from solar images recorded daily by the MDI instrument on board the space-based SOlar and Heliospheric Observatory (SOHO).

Far Side of the Sun
3.05.2001

You may think it's impossible to see through the Sun, but maps of the Sun's far side are now made routinely by instruments on board the sun-staring SOHO spacecraft. This is one such map from April 12.

Sunspot Stack
19.04.2001

Welcome to multiwavelength astronomy! From top to bottom, these stacked panels show the largest sunspot group in a decade in visible, extreme ultraviolet, and x-ray light. All were taken on March 29, around...

Solar Neutrino Astronomy
17.05.2001

Neutrinos are subatomic particles generated by the nuclear reactions which power stars like our Sun. Flying outward from the Sun's core, they easily pass through the Sun (and almost anything else!) unimpeded and should be detectable by earth-based neutrino "telescopes".

A Backward Sunspot and the New Solar Cycle
30.08.2006

Why is sunspot 905 backwards? Perhaps it is a key marker for the beginning of a new magnetic cycle on our Sun. Every 11 years, our Sun goes through a magnetic cycle, at the end of which its overall magnetic orientation is reversed.

Large Sunspot Group AR 9393
11.04.2001

The largest sunspot group of the past ten years crossed the surface of the Sun late last month and early this month. The group was designated Active Region 9393 as it was the 9393rd region identified since counting officially began in 1973.

Rivers in the Sun
4.09.1997

The surface of the Sun is shifting. By watching sunspots, it has long been known that our Sun rotates. It was also known that the center of the Sun rotates faster than the poles.