Royal Astronomical Society of Canada (RASC)
Tue, 08/30/2022 - 23:03

Just curious how other folks are counting Sunspots and Groups on today's solar disc? 

Active Region 13089 is huge....with multiple groupings and numerous sunspots, but they are all clustered very close together. Some are encircled by their own penumbra, some not. Freckles (I'm assuming some true spots, others pores) all over the place and inter-mixed. 

If you haven't been able to get outside and take a look, here is a link to a image of the Active Region (Forum won't let me [file upload] an image??):

I just want to count my observations reasonably consistent with how everyone else does it. If I use penumbra as a guide, then through my 8" Newtonian, I count about 6 Groups and approximately 16 spots. Or, should I be reporting this a 1 large group, with 16 spots? Anyone?

Appreciate any feedback.



Groups and Sunspot counts

Hi JL,

Even though 3089 is a large Active Region it probably should be counted as one large group perhaps E in size on the Zurich scale. It then comes down to estimating the size of the sunspot[s] in the group and not counting pores (spots that might last between 1/2 hour and 1 hour). I counted it yesterday as 1 group with about 24 sunspots. 

Other's may have ideas for counts on this one?  

Some references: