Sunday, May 13, 2012


There's a huge sunspot at the moment: I have never tried to do astrophotography of the sun before (at least, with a telescope).  This 1/180th exposure with a 1143mm f/9 refractor really doesn't convey the level of detail that is visible through the eyepiece.

I have gray scaled it.  For some odd reason, there are circles here that do not appear on my local version--some weird compression artifact of Blogger's upload?  (On some computers, but not on others.)  Yes, it seems.  I ftped the picture, and it looks much better after you click on the picture to maximize size.

To get a sense of scale: the Sun's disk is 865,000 miles across.  The big sunspot in the lower right is about eight times the diameter of Earth.

FTPed Sunspots

Here's some more detail on the largest sunspot group.  And yes, this is not far from what it looked like through the eyepiece at 91x, with the darker umbral zone and the lighter penumbra:

IN case you wonder what a refractor this size looks like:

This is what most people think of when they think "telescope."


  1. Hey Clayton! For some reason, when I saw the telescope in the foreground, with the car behind, I couldn't help thinking of the line from Jaws, so "I think you're gonna need a bigger car."

  2. Actually, no. I use the folding tripod if I need to transport it--and then I can fit it (and even my 8" f/7 reflector) in the Corvette.