Hello,
Today’s 4419 region was very complicated. The official count is 21 spots but I am having trouble getting past about 13. Can anyone assist? Please see the attached image from spaceweatherlive.
Spot counts are always hard IMHO! How to decide if something is an umbral true spot surrounded by penumbra or just a pore, for example. Time is a factor as well. If you count at 13:00 UTC and come back at 14:00 UTC and count again you most likely will get a different count. Especially, if a group is active.
Tell us more about your observing system, are you counting visually?
Do your best visual estimate at around the same time of day and report that to the Solar Section. They will know what to do with the data they receive.
Jim (DEY)
Hi Jim,
I am VERY new to this. Just started about a week ago. I usually try at about 10AM local time. I am using an Orion Mak 1300 FL. I use a Lunt zoom eyepiece typically at about 90X. I just started using an erect-image prism diagonal so now I don’t have to worry about flipping things left and right! My brain was really having trouble with that!
I am pretty good at identifying the major spot type but have not quite figured out how to estimate the size/distance to differentiate D, E, and F.
I am definitely not good enough to report any data yet. But I am improving. Still not sure how to interpret the angles reported by Tilting Sun but I try to match my drawing with the daily synoptic map at NOAA.
Fun stuff!
Dave
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This is a very complicated spot. I have having trouble determining the third letter in the spot classification. Previously it was listed as I for the third letter. That makes sense. Today there are more intermediate spots and it is now listed as O which means “few or none”. It seems the classifications are backwards. Can anyone explain this?
Thanks
Hi Dave,
I have been observing sunspots for just over five years now and am one of the members (and now coordinator) of the observation group established by the late Leif Svalgaard to set the baseline for historical sunspot counts.
What you need to realise is that no two people will count the same number of sunspots, except by pure chance. The same applies to group numbers (although they are more likely to count the same number in that case). Ultimately, it is about obtaining consistent results so that your k-factor can be determined [R = k * (10 * G + F)], something that is done automatically for you in the long run based on your data. What I found useful (and sometimes still do) is to verify the result with one of the major observatories:
SILSO: https://www.sidc.be/uset/
(for the archive see SIDC - Solar Influences Data Center)
Locarno: Specola Solare Ticinese Drawings Archive
Kanzelhöhe: Kanzelhöhe Observatory Synoptic Archives
If you look at their archived drawings, you will see that even they differ in the number of sunspots and groups.
HTH
best wishes,
Nicolàs
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Hi Nicolàs,
Thanks for the reply. I look forward to actually contributing some real data soon. Yes, I realize there is some variability and my seeing isn’t always so good so I know I will typically be undercounting. I just don’t want my k factor to be huge.
Also, I am trying to really understand the classification system and this spot in particular went from an “i” to an “o” in the third letter and that doesn’t make sense to me. Can you explain that given the images as presented?
And thanks for the links. Always good to have more comparisons to look at.
Cheers,
Dave
Hi Dave,
our group does not need to do the classification as we are merely looking for the effect of singlet telescopes on the sunspot/Wolf number, so I am not an expert on that part (far from it even). There is, however, good literature on the classification method:
T.S. Ringnes, ‘Waldmeier Classification’, in: Institute of Theoretical Astrophysics, University of Oslo, Report No.83, (1986)
Available from: https://inis.iaea.org/records/cbfhx-n6w88/files/18043879.pdf
cheers,
Nicolàs
Thank you for the link. Unfortunately, that document only discusses the main spot type classification (the first letter in the triplet). There must be a good reference with examples somewhere…
Hi Dave,
Indeed, you need the McIntosh Classification system.
There are a few examples at the top of the page.
Also more info in the following article:
McIntosh,P.S., “The Classification of Sunspot Groups”, in: Solar Physics 125, pp.251-267 (1990)
Nicolàs
Thanks for the links. Very helpful. Yes I was trying to learn to use the McIntosh system. The example pictures were helpful but also somewhat confusing. I think I may need to be happy with just getting the main classification (the first of the three letters) correct.
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