Welcome to the new central Web site for the International Sunspot Number !
We designed those new Web pages to offer you an easier access to the existing sunspot data and to the associated information. This new communication platform is destined to grow over the coming months and years, with new data and graphical products and new sections providing extra information about the World Data Center and its worldwide observing network.
This initial version already features new items like a dynamical plot of the latest Estimated sunspot number (EISN) updated every 5 minutes, new data descriptions and formats (CSV for direct import in your favourite spreadsheet) or the FAQ section.
This new window on the Sunspot Number is just the visible part of an ongoing modernization and expansion of the historical Sunspot Number series that started several months ago. As you probably noticed, in order to reflect this new big step forward and the new scope of our World Data Center, we gave it a brand new name and logo: SILSO for "Sunspot Index and Long-term Solar Observations".
Please explore the new sections and don't hesitate to make comments and suggestions.
New ideas are always welcome and we will strive to implement them while the site is maturing. Stay tuned for upcoming changes and new features !
Frédéric Clette
WDC Director