I’ve been actively making Sunspot observations and submitting then to the BAA & AVVSO Solar databases since August 2022. But today, I made my 100th observation of the Sun. In the great scheme of Solar observing I guess this isn’t a particularly high number of observations, but it’s a milestone nonetheless.

Things have changed over those 100 observations. The most dramatic of which is the accuracy and information recorded now. To illustrate this, there is my first ever drawing with the accompanying Helioviewer overlay to show in what hemisphere the spots are in.

I wasn’t showing my workings on group calculations, so if I were to count this drawing today, I would have counted 4 groups and not the 5 that I submitted. The drawing only reflects the groups and didn’t provide any context of how those groups looked. The accuracy of the placement was also a bit hit and miss then too.

Compare that with today. My drawing sheet shows the orientation of North and West and this is aligned to Equatorial East/West of the mount using a crosshair reticle. I’m now calculating ‘Q’ using the Zurich Classification. This is done at the eyepiece, but if I find that when loading the scan into Helioviewer that the group is smaller or larger than the 10-15 degree limits, then I can change the classification before posting. After I have made the drawing, I do compare it to the SIDC daily drawing – if there is one – to check my results. Any massive howlers are corrected, but generally, I leave things as I saw them and learn from the experience until next time.

Most of this data never sees the light of day, so I’ve presented it here with various graphs based on that data, in order that it is easier to digest and understand.

Sun Group, Spot Counts & ‘R’

This is a count of the number of Groups and Spots over the whole Solar surface at the time & date of the observation.

The ‘R’ or Wolf Number is calculated as follows. Let us say that you count 3 groups consisting of 3 spots in the first group, 8 spots in the second group and 1 spot in the third group. You now have 3 groups, and 12 spots. To record the sunspot number for the day you need to multiply the number of groups by a factor of ten, i.e. 30, and add it to the number of spots recorded i.e. 12, giving a total of 42 which is the sunspot number referred to as ‘R’. 

Sun Group and Spot Counts by Hemisphere

This is a count of Sun spots counted in the Northern and Southern Hemispheres at the time & date of the observation.

‘Q’ Number or Quality

The Q Number is based on a value assigned to each group visible each day using the Zurich sunspot group classification.  So an A group has the value of 1, a B group 2 etc. with the more complex groups having a higher number.  For each daily observation, these numbers are added together to give a Q value for each day.  Further details can be found in the BAA paper ‘Analysing sunspot activity: A qualitative and quantitative approach’, Frank J. Ventura and Tony Tanti, J. Brit. Astron. Assoc., 98, 282-286 (1988).

number of spots recorded i.e. 12, giving a total of 42 which is the sunspot number referred to as ‘R’. 

Daily Observations


There are the actual figures submitted to the BAA and AAVSO and chronological order, with the latest observation at the top of this sheet.