Like observing the planets in our solar system, observing the sun on a daily or weekly basis gives one an intimate knowledge on its workings and beauty. I have enjoyed watching the storm clouds on Jupiter and the Great Red Spot change over time. But watching the sunspots on the surface of our sun and their effect on space weather throughout our solar system is quite cool, dare I say scorching!!! Especially as we approach solar maximum.
By regularly counting sunspots you can determine for yourself if solar activity is increasing or decreasing and might even catch a solar flare. In Part 1 I introduced the formula for calculating your own sunspot number:
R = k (10g+s)
R is the sunspot number; g is the number of sunspot groups on the solar disk; s is the total number of individual spots in all the groups; and k is a variable scaling factor that accounts for observing conditions and the type of telescope used.
You don’t need to know your personal scaling factor “k” to log your own sunspot number. Just set it equal to 1. However
k = Rp/ISN
Where k is your personal scaling factor, Rp is your sunspot count (Rp = 10g+s) and ISN is International Sunspot Number as calculated by the The Solar Influences Data Analysis Center (SIDC).
At the end of everyday SIDC publishes a Provisional ISN that you can use as the ISN. It is within 5% of final value so you don’t have to wait until the end of the calendar month to get the Definitive ISN. You can get the daily Provisional ISN here along with an Estimated ISN for the upcoming day (and use estimated if provisional is not reported). This data can be e-mailed to you once a day by signing up here.
SIDC has calculated the average sunspot number for past months and came up with this nice graph showing is change over several years with a prediction of when the next solar maximum will be (early 2013).
Don’t wait for the solar max to start observing. As you can see by this graph there are months, let alone individual days, that the sunspot number can “flare” into the 100’s. In fact flares don’t depend on a lot a sunspots to happen – one big sunspot group is enough.