1
$\begingroup$

What is a place to find raw numbers of sunspots from the past, as counted by sun observers ?

I have already visited 100+ of websites (NOAA, NASA, ESA, Japanese Institute ..) and what is offered is calculated number of sunspots, Wolf number or modified Wolf number, still called sunspot number or raw number of spots.

I can get raw number of spots, as counted by observer from Royal Observatory Brussels, read from hand-made sketches, but one by one, not offered as a database txt or cms file.

I write short conference paper and get historic raw sunspot number counts from bulletines by Rudolf Wolf and others, as old as of the 1850 year.

It's ok, if you count sunspots and save your daily count to a file. But today, counted numbers of sunspots by an individual observer, have been replaced by calculated sunspot indexes, called International Sunspot Number, Estimated Sunspot Number, Wolf number.

I am sure, raw number of sunspots, as counted daily by an abserver, is saved and database is available somewhere on the internet, but I tried hard, contacted many space weather scientists, researchers, contacted NASA, NOAA, ESA and still no success.

thank you

$\endgroup$
2

1 Answer 1

0
$\begingroup$

Spaceweather.com have an archive query on their landing page that allows you to search the "Daily Sun" by day, month and year. Is that what you're looking for?

$\endgroup$
2
  • 1
    $\begingroup$ what is published by Spaceather.com is Wolf number. Sunspot number: 89 What is the sunspot number? Updated 04 Jan 2023 I emailed webmaster and owner of this site and got no reply. Sunspots are counted by sun observer: 1, 2, 3, ... (one, two, three ..) Wolf number is calculated by formula: R = 10g + f where g is the number of groups of sunspots and f is the number of individual spots. I need "f" numbers since "f" is counted vs. Wolf number is calculated. Wolf number is not number of sunspots. Wolf number is Sunspots based Index $\endgroup$
    – darius
    Jan 4, 2023 at 21:44
  • 1
    $\begingroup$ read the link from this site spaceweather.com/glossary/sunspotnumber.html called: The Sunspot Number "As a rule of thumb, if you divide either of the official sunspot numbers by 15, you'll get the approximate number of individual sunspots visible on the solar disk if you look at the Sun by projecting its image on a paper plate with a small telescope. So he is aware of, the real number of sunspots is one counted by sun observer. There is no official sunspot number, since spots are counted by humans and numbers can be verified against saved images of solar disc. $\endgroup$
    – darius
    Jan 4, 2023 at 23:04

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .