The Original Maunder Diagram
butterfly diagram drawn by W. Walter Maunder and Annie S. D. Maunder
in 1904 has been on display for some time at the High Altitude Observatory in Colorado.
International Astronomical Union Working Group on Eclipses:
Pasachoff's eclipse expeditions from Williams College and elsewhere:
values of the solar constant as measured by the VIRGO experiment on
SOHO, along with past measurements from several spacecraft, are
available on line at
http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant from the World Radiation Center in Davos, Switzerland.
or, as measured by NASA's ACRIM3 experiment on ACRIMsat, at http://www.acrim.com
Solar Dynamics Observer satellite
Sun Watcher solar telescope on ESA's PROBA2
And if you want to see if it's clear on Mt. Wilson, check the towercam on the 150-foot tower at: http://www.astro.ucla.edu/~obs/towercam.htm
From Solar News, The Electronic Newsletter of the Solar Physics Division American Astronomical Society, Volume 1999 Number 15:
The 60' Solar Tower, at Mt. Wilson Observatory now provides current solar images to the internet community. Daily GIF images are provided every clear morning at: http://physics.usc.edu/solar/
Daily images include a filtergram, dopplergram, velocity map, and magnetogram in the chromospheric sodium D-line region of the solar atmosphere. All GIF images can be viewed at 256x256, 512x512, and 1024x1024 pixel resolution. The original 1024x1024 fits images, from which the gif images are processed, are also included.
Past images can be searched for at; http://physics.usc.edu/solar/search_images/search.html
The 60' Tower continues to acquire two 1024x1024 pixel filtergrams each minute for up to 12 hours per day. From each pair of filtergrams a full- disk dopplergram is computed later. Plots of daily hours of filtergram observations, lists of temporal coverage of computed dopplergrams, and lists of temporal coverage of multi-day time series and power spectra will be provided online in the near future.