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Post by justsomeguy on Mar 23, 2012 11:11:55 GMT
Depends on what you mean by sun spot trend... If you mean the Livingston and Penn work with Dr Svalgaard there are lots of updates in that thread. It still looks to be trending lower to me:  Has the slope changed recently Dr Svalgaard? |
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Post by lsvalgaard on Mar 24, 2012 5:32:34 GMT
Depends on what you mean by sun spot trend... If you mean the Livingston and Penn work with Dr Svalgaard there are lots of updates in that thread. It still looks to be trending lower to me: Has the slope changed recently Dr Svalgaard? Adding a year or two does not give enough information to definitely claim a changing slope. One has to look at the whole deal. But, generally, I would say no change in the trend that is significant one way or the other. |
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Post by justsomeguy on Mar 24, 2012 5:56:53 GMT
Thank you. Is it possible that their is some lower threshold above 1500 gauss? Namely there would be fewer sunspots during a grand minima, but still a few. There were still some sunspots during the Maunder but fewer? The data seems to indicate that might be true (a few sunspots from 1645-1715).  |
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andor
Level 2 Rank
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Post by andor on Mar 24, 2012 13:11:32 GMT
I would say then we use and old piece of smoked glass and a 17th century telescope, observe the sun and then count the spots and we would get close to maunder's way? It appears that nowadays they count spots which Maunder would never have seen!! In the Maunder minimum, was the total spots per day counted or only the new ones?
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Post by lsvalgaard on Mar 24, 2012 14:48:41 GMT
I would say then we use and old piece of smoked glass and a 17th century telescope, observe the sun and then count the spots and we would get close to maunder's way? It appears that nowadays they count spots which Maunder would never have seen!! In the Maunder minimum, was the total spots per day counted or only the new ones? The modern sunspot count is based on [or corrected down to] the count made with small telescopes [8 cm opening and 64x magnification]. For the years 1865-1893 Rudolf Wolf used this very telescope  |
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Post by justsomeguy on Mar 24, 2012 15:03:47 GMT
You look good with that telescope.
So you do believe that there were some spots during the Maunder, as the count states?
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Post by lsvalgaard on Mar 24, 2012 16:12:22 GMT
You look good with that telescope. So you do believe that there were some spots during the Maunder, as the count states? some spots were indeed observed, but it is hard to calibrate those to the modern counts. We know that the cosmic ray modulation during the MM was as strong as today, so the solar dynamo was certainly running and there was a solar wind. |
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Post by jcarels on Mar 24, 2012 20:28:30 GMT
If I use my Galileoscope and project the sun on a white paper, there are almost no sunspots...(so we could be at a minimum). If only I could have a look at observations from that time.
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Post by THEO BAKALEXIS on Mar 24, 2012 20:58:04 GMT
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Post by lsvalgaard on Mar 24, 2012 20:58:13 GMT
If I use my Galileoscope and project the sun on a white paper, there are almost no sunspots...(so we could be at a minimum). If only I could have a look at observations from that time. yeah. The spots now are weak and don't look much: www.specola.ch/drawings/2012/loc-d20120324.JPG |
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Post by justsomeguy on Mar 25, 2012 23:20:54 GMT
If I use my Galileoscope and project the sun on a white paper, there are almost no sunspots...(so we could be at a minimum). If only I could have a look at observations from that time. yeah. The spots now are weak and don't look much: www.specola.ch/drawings/2012/loc-d20120324.JPGIs that significant? I mean, we do correct for the number of sunspots seen on average (the 0.6 correction) but does that correct for the number seen in a time like this when the sunspot have an average smaller size and are less likely to have been seen "back then"? |
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Post by lsvalgaard on Mar 26, 2012 1:15:48 GMT
Is that significant? I mean, we do correct for the number of sunspots seen on average (the 0.6 correction) but does that correct for the number seen in a time like this when the sunspot have an average smaller size and are less likely to have been seen "back then"? No such correction as the present. One of the topics for discussion at the SSN workshop in May is precisely how to deal with this ssnworkshop.wikia.com/wiki/2nd_SSN_Workshop |
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Post by justsomeguy on Mar 27, 2012 19:21:01 GMT
So, for example, how many spots could you see using the Wolf scope above? Could you see any of the small spots north of the sun's equator?
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Post by lsvalgaard on Mar 27, 2012 19:56:10 GMT
So, for example, how many spots could you see using the Wolf scope above? Could you see any of the small spots north of the sun's equator? I would estimate to see five of them, and classify them as all part of the same group [and not of two groups as SIDC did today] : www.specola.ch/drawings/2012/loc-d20120327.JPG |
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Post by jcarels on Mar 28, 2012 15:05:46 GMT
Looked like 2 different groups to me. I've classified one group as Dri 17. The other group didn't had a real spot in it, only pores.
Today I used a 50mm refractor and projected the sun. I could only see 3 groups and 5 sunspots! R=35. Compare that to my observation with a 10cm refractor with Herschel prism: 6 groups, 40 sunspots. R=100
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