# How to count sunspots?

Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 10/28/2014 - 01:54

Ok,

I actually read a thread from back in April of this year, that helped a little.

And Ialso  read a handbook written for the Astronomical League.

But I need to have this dummied down for me a little?

So If I'm  using the SunEntry system to enter my data.

If today while observing the Sun I see:

5 independant sunspots

2 groups containing a total of 5 sunspots

In SunEntry do I enter a 2 for groups and 10 for sunspots?

David

Affiliation
American Association of Variable Star Observers (AAVSO)
Wolf Number.

Hi David.

the Wolf. Number:,

Wolf number (10g + f)

5 independant sunspots = 5 groups (50) + 5 sunspots (5)= 55

2 groups containing a total of 5 sunspots=2 groups(20) + 5 (5) sunspots.= 25

Wolf: 80..

regards

In SunEntry do I enter a 2 for groups and 10 for sunspots?

Zuric groups and sunspot counts

There are two important things to understand about counting groups and sunspots, I think. First the AAVSO, since the begining in 1944, has adopted the Zurich classification of groups and sunspots:

http://www.aavso.org/zurich-classification-system-sunspot-groups

Second, this classification was originally from Wolf the director of the Zurich observatory back in 1860:

There are other classification schemes for sunspot counting, McIntosh, Boulder, etc. (See attached .ppt), however since the AAVSO has a long history of using the Zurich scheme, it would be preferable it that method were used.

Hope this helps.

Rodney

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

Thanks for taking the time to respond to my post.

That being said I think you guys might have missed the second part of my question, "What do I enter into SunEdit"?

Athough after I little tinkering with SunEdit it seems that there are two options for entering the values for "Group and Spots"

I could enter to total groups 7 and total spots 10 which give the total Wolf count of 80.

Or I can enter two records one for sunspots and one for groups?

Thanks again.

David

Affiliation
American Association of Variable Star Observers (AAVSO)
Hi David,
I think you got it.

Hi David,

I think you got it. But to be clear:

1. Add up the number of groups. Note that a group may have just one spot. Enter that number in the 'Groups' box in SunEntry. So in your example that is 7.

2. Add up the total number of spots. Enter that number in the 'Spots' box in SunEntry. So in your example that is 10.

Given 1 and 2 above, SunEntry will automatically calculate and enter the Wolf Number, so there need to enter it manually. In your example SunEntry will calculate 80 for the Wolf Number.

There is just one record for each day you observe (you should only make only one observation per day).

John

Affiliation
American Association of Variable Star Observers (AAVSO)
John,

I am really sorry,…

John,

I am really sorry, but definition of a group is clear from theory of sets, from mathematical topology.

". Note that a group may have just one spot

Nope, we should reject such approach.

Group is a group and is made of 2 or more elements.

Activity Region can be represented by a single sunspot but Activity Region and Group of Sunspots represent different terms under standards adopted by NOAA.

Computers can easily identify zero-sunspots regions in the solar disc, as regions of some type of solar activity, making Wolf number to grow to the sky.

Can you name a person with NOAA responsible for the ". Note that a group may have just one spot" agenda ?

Rudolf Wolf lived counting raw number of sunspots and was happy.

Every sun watcher, still counts raw number of sunspots.

There is no public interest in making Wolf number to grow artifficially, to claim solar activity to be on rise.

Affiliation
American Association of Variable Star Observers (AAVSO)
sunspots counting

Hi:  Great and have  a good time.  I still enjoy checking out the sun. Hope to bring my scope to the AAVSO. annual meeting.  I found my time being taken up by alot of caregiving these days. Best HNL

Affiliation
American Association of Variable Star Observers (AAVSO)
How to count raw number of sunspots?

I have spent the last 6 months, trying hard to learn, how the raw number of sunspots is counted

and failed to get any answer or instruction, manual, supported by images of the sun disc, stating number of sunspots counted for enlarged image of every group .

I would love manual like this one

https://www.aavso.org/zurich-classification-system-sunspot-groups

stating number of sunspots within every group

thank you

Affiliation
American Association of Variable Star Observers (AAVSO)
How to count raw number of sunspots

Hello Jack,

Figuring out what counts as separate groups and spots is notoriously tricky - especially when there are a lot of both, like there are now.

Have you read the Solar Observing Guide for starters?
https://www.aavso.org/solar-observing-guide

It may not have all the answers to your questions, but I think it is a good place to begin and offers some suggestions.

Other resources available include:

• A CHOICE course on counting sunspots which will be taught in September: https://www.aavso.org/choice-astronomy
• Links to other information on the Solar Section webpage: https://www.aavso.org/solar

I hope this will help.

Best wishes,
Sara

Affiliation
American Association of Variable Star Observers (AAVSO)
.

Thank you Sara,

can you count raw number of sunspots in the following images of solar disc ?

https://spaceweather.com/images2022/16dec22/hmi1898.gif

https://spaceweather.com/images2022/16dec22/hmi4096_blank.jpg

Affiliation
American Association of Variable Star Observers (AAVSO)
Counting Sunspots

Hello Darius,

No! Please do not use images from the web (i.e. Spaceweather, SOHO, etc.) or even your own images for counting sunspots. The reason is that images show things that your eye cannot see - either because they are higher resolution or use a different wavelength of light that your eye can see. This will cause your counts to be higher and bias the results.

The AAVSO 's data is used to compute the American Relative Sunspot Number (Ra) which is based on VISUAL observations going back to 1944. If people count solar activity using images this will negatively affect the long-term usefulness of this index.

If you have a small telescope and a good solar filter, you can learn how to count groups and spots safely using our Solar Observing Guide. Then you can submit your observations with SunEntry which will calculate your Wolf Number for you. By combining all of the data received, the daily Ra number will be computed and the results are published each month in the AAVSO Solar Bulletin and shared with scientists around the world.

Thank you for asking this excellent question!

-Sara

Affiliation
American Association of Variable Star Observers (AAVSO)
Web-based astronomy is ok…

Web-based astronomy is ok today since satellite based telescopes work live and remotely and data are radio/ microwaves transmitted to the ground

for analysis.

High-res images of solar disc are ok for training and the visual count of sunspots, since 50% of pro telescopes in US are today closed due to severe winter conditions

and there is a limited use of backyard telescopes in the winter time.

High-resolution of images is success not an obstacle.

Could you tell me what things are shown in the images below

https://spaceweather.com/images2022/19dec22/hmi1898.gif

https://spaceweather.com/images2022/19dec22/hmi4096_blank.jpg

you cannot see with your eyes ?

Just contacted Wilson Observatory and the projected image of solar disc, used for sketching sunspots is of much higher optical resolution, since not affected by image

pixelization.

I get images of solar disc from NASA, NOAA, ESA and 10+ more agencies on a daily basis and images from Brussels, coordinator opf the International Number of Sunspots are not of good quality, resolution is not high, images are sometimes blurred or not accessible at all due to weather conditions.

As NASA Citizen Scientist I would like to discuss web-based astronomy to learn more from peers and pros.

We calculate raw number of sunspots anyway, used for calculation of Wolf number.

Some observatories publish: raw number, number of groups and Wolf number calculated.

The Chinese observed the sun 1,000 years ago and have seen large sunspots with naked eye, not the case today.

Affiliation
American Association of Variable Star Observers (AAVSO)
SpaceWeather images

Darius -

Spaceweather images are useful for training purposes of discussing groups, as has been done elsewhere in this thread, because they include numbers that we can make note of to clarify discussion. Sara is right that you can't assume that what it in the image is what you see through the telescope. You can also bias yourself if you think there is something you SHOULD see but can't - if you can't see it, you shouldn't count it! Here is an article about the good, bad, and ugly of consulting such images: https://app.aavso.org/media/jaavso/2793.pdf

KL

Affiliation
American Association of Variable Star Observers (AAVSO)
I study Space Weather as…

I study Space Weather as NASA Citizen Scientist, calculate jets, flares, CMEs and build tools to study volumetry in space weather.

Sunspots should not be considered a by-product or a thing of past, since clearly detectable among the flares, jets.

I target highest resolution images of solar disc from Parker Probe, ESA 92Mpix since I build live SunGlobo model to view  the Sun 360 degrees in stereoscopic imaging.

So I would really apprecciate your help in comparative studies : telescope imaging vs. Web-based astronomy

thank you

computer models for sunspot counts

Hi Darius,

We do use Jan Alvestad's (https://www.solen.info/solar/) computer routine to estimate sunspot and group counts from the SDO - HMI data, (STARA routines) described in this document by Verbeeck et al. - article: (https://arxiv.org/abs/1109.0473) . HOWEVER, SDO-HMI daily count estimates are not included in the AAVSO Ra index as calculated by the Shapley method (http://iopscience.iop.org/article/ 10.1086/126109/pdf).   Reason being we are trying to maintain continuity with visual observations from small telescopes (including projection method). As the sunspot time series we track goes back 400 years to Galileo.

Rodney

Affiliation
American Association of Variable Star Observers (AAVSO)
ok, I just read and watched

ok, I just read and watched

Larsen,  JAAVSO Volume 40, 2012374
The Effect of Online Sunspot Data on Visual Solar Observers
Kristine Larsen
Physics and Earth Sciences, Central Connecticut State University, 1615 Stanley
Street, New Britain, CT 06053; larsen@ccsu.edu

https://app.aavso.org/media/jaavso/2793.pdf

How-to Sessions (2022)
AAVSO How to ['Count' Sunspot Activity]
AAVSO HQ
1.59K subscribers
239 views  19 Aug 2022
With instructor: Dr. Kristine Larsen (Central Connecticut State University)
Original broadcast date August 6, 2022

https://youtu.be/aeYM3WVCxc8?t=621

could you explain me why a single sunspot should be counted as a group ?

It doesn't matter if you count raw number of sunspots, as published by the Bruxells Observatory

but it matters if your calculate Wolf's number since it adds "10" to the sum and the final result.

Affiliation
American Association of Variable Star Observers (AAVSO)
Why is a single spot also a group

Think of "groups" as "regions of activity" - it doesn't matter as much how many individual spots there are in that active area as that there IS an active area. That is why groups (active areas) are weighted by a power of 10 in the equation R = 10g + s.

So an isolated spot marks a distinct area of activity (g=1) and it is made of 1 spot (s=1) so if that is all there is on the sun that day R = 10 X 1 + 1 = 11.

- Kris Larsen

Affiliation
American Association of Variable Star Observers (AAVSO)
how could I ?

regions of…

how could I ?

regions of activity are computer generated by NOAA

groups of sunspots belong to theory of sets (math, topology)

There is no group made of a single element,

so NOAA generated mismatch, implementing single-sunspot groups

What is ok for computer identified and generated Activity Regions

is not ok for groups observed with naked eye and manually sketched for centuries.

Do you know who is to blame at NOAA for the idea of single sunspot groups ?

Computer assisted image processing can easily generate , identify none sunspot Activity Regions resulting in Wolf number to grow to the sky

Who is at NOAA in charge of the concept of single sunspot groups ?

5 years it was easy to chat over Twitter, today Twitter is down, no traffic, email is flooded with marketing spam,

so your site is the only active place in our galactic for sunspot friends ;)

3 years of covid19 killed any social activity over the Internet

thank you