American Association of Variable Star Observers (AAVSO)
Thu, 10/30/2014 - 17:58

Where can I get yesterday's sunspot count?




sunspot counts

Hi David,

Here are the averages of groups, sunspots and Wolf numbers for these this last week:

Day g s Wolf
22 5.20 84.20 136.20
23 5.27 79.60 132.27
24 5.75 76.58 134.08
25 6.08 77.92 138.75
26 5.64 65.18 121.55
27 4.56 58.56 104.11
28 5.00 47.17 97.17
29 6.33 23 86.33

These are averages of those observers who enter daily data into the SunEntry database using the on-line form. All observers data will not be in the database until after the 15th of November so these are provisional averages.


American Association of Variable Star Observers (AAVSO)
Thanks for the


Thanks for the information.

I planning on starting my Sunspot counting program as soon as I get my filter next week.

And I would like to compare my daily/weekly/monthly numbers, are those numbers published or is there a way for me to retrieve that information myself?


Thanks again,

David (JDAC)

daily data

Hi David,

The monthly numbers are published in the Solar Bulletin:

The best rational I can give for not publishing daily or weekly numbers is historical. In the past there was no computer email nor an electronic database, only the paper Solar Bulletin mailed to those who requested it on a monthly basis.

The other reason is that, if possible, there's a need for each observer to find their own method for counting groups and sunspots; given that they understand the original Zurich classification and the reason for the American Relative Index. Then after 100 or more observations in the database they will be assigned a k - factor, which 'aligns' their monthly values to all other (on average 65 to 70) observers. The 'golden rule' here is that you are consistent in your counting method. It's assumed that after 100 observation submissions you'll pretty much be a consistent counter of groups and sunspots.

I can post weekly averages, with the understanding that there are only about 17 observers who post their daily counts in the SunEntry database. The other 50 or so observers upload their text files to SunEntry at the end of the month, or send their data files to Kim Hay to upload those monthly data.