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Butterflydiagrams of the Sun
Since 1976 I observe
the Sun systematicly. With every observation I also count the number of
sunspots and do I make an exact positiondrawing. From 1980 this happens with a
90mm/f1300mm refraktor. The drawings are 150 mm in diameter with an accuracy of 99%.
This means that the drawaccuracy on the centre of the sundisk is secure within
1 heliographical degree. A computer is used for storing and computing this
data. So it's possible to make a butterflydiagram. In a butterflydiagram the
average latitude of the leading- and following sunspots from appearing groups
of sunspots is shown through the time. It looks like that at the beginning of
the solarcycle sunspots are appearing at higher latitudes on the solardisk.
When the cycle goes further the sunspots occurs more and more closer to the
Sunequator. When a diagram is made of all of this positions it looks like a
butterfly. The first observations with accurate positions were made in 1750.
From 1854 every cycle got a number. The first "butterfly" in the
diagram below is from 1980 and has number 21. The now disappearing
sunspotscycle is the 23th. The first sunspots from the 24th cycle will come up
some years later! The most sunspots which are now appaering are mostly situated
near the Sun's equator. In the long-period picture You can see that the cycle
23 is now on it's end. Complex groups to from McIntosch
scale "E" or "F" are rarely visible from now on, but
the solar maximum holds long this time. Now in June 2002 there are still lots
of sunspots visible on the solar disk! To find out when the new solar-cycle has
started you have to look at the polarities of the sunspots. This tell us of a sunspotgroup
belongs to the new started cycle or not. The polarity from sunspots of the new
cycle are the opposit of the old ones. In this unique site you find two
butterflydiagrams of the sun:
1. View of the last 37 years
2. Butterflydiagram of the last year
Diagrams with counted number of sunspots
You can find some diagrams with counted sunspots through the years
More about actual Sunobservations look here
More about daily magnetograms look here
More about myself:
My Name is Bob van Slooten and I live in Amersfoort,
I am an amateurastronomer and started the observations in 1976 at the house of
my parents. In 1987 I moved to the "Schothorst" public stardome. This
location allowed me to make observations through the year. I could watch the
whole day if there is was a clear sky. There were normally about 250
observations possible in a year. In april 2001 I had to move to my house.
(Mouth and footdisease by cows and sheep in the neighbourhood of the park) I
found that the frequence of looking to the sun overthere does not differ very
much. I think there are more observations possible, because don't have to
travel. I can immediately watch the sun when a usefull clear spell in the
clouds appears. I have a good view to the east and south sky.
For comments or more information
about this page, please E-mail me!
permitted if the source is mentioned.
* * * Last
update: 01-02-2014 * * *
Images of the South African sky
On the the next pages You can read about a visit I've made to
"Spreeufontein" observatory in South Africa. This nice Observatory
which has equipment to make excellent pictures of celestial objects visible at
the Southern sky. For unbelieveble pictures please click the following link in
your favorite language!
See the nice pictures of the southern Sky!
mooie foto's van de zuidelijke hemel!
The person behind
this page is against unnecessary and meaningless violence; in Dutch spoken: Ik
ben tegen onnodig en zinloos geweld
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