American Association of Variable Star Observers (AAVSO)
Sat, 01/25/2014 - 16:04

I've been doing sunspot counts for at least 20 years with several telescopes.  I'm presently using a 130 mm APO refractor stopped down to 80 mm with a Baader Herschel wedge.  I put an H-alpha ERF on the front of the telescope to preserve the optics.  I live in Maryland where it occassionally gets cold!   During warm weather the solar image is very steady and it is easy to make my counts.  However, when it is cold the image gets very unsteady and I know my counts suffer.  Wouldn't this affect my "k" value?  Or does the fact that my reading is "fair" or "poor" take that into account?  And - is there a way to get a steady image during cold weather?  Keeping the "scope on the sun for a long time doesn't help.

k -factors

Hi Jay,

I'm sad to say I've only worked with a Herschel Wedge once.  So, I don't know about warm or cold weather viewing.  Perhaps someone with experience about this will respond. 

K - factors, at this time, are calculated for those observers who have over 100 observations within the last two years in the SunEntry database.  Hopefully this covers all seasons.  We know from statistical analysis that seeing conditions are significant. See pages 9 - 10 of the attached analysis by Jamie Riggs.  But, at this time we do not take this into account.