Sunday, January 29, 2012

The Sun

I recently gained access to a Coronado Personal Solar Telescope (PST). The PST is specially designed for solar viewing. It has a built-in filter for viewing Hydrogen Alpha (H-Alpha), which is one of the wavelengths of light emitted by hydrogen atoms that are being "stimulated" by ultraviolet radiation. It is one of the most common colors visible from stars since their outer layers are primarily composed of hydrogen atoms. H-Alpha is in the red part of the visible spectrum.

This morning I attached the PST to my Vixen Super Polaris mount and pointed it at the Sun. What I saw blew my mind! The detail was amazing! I could see prominences, the granular surface of the sun, and a sun spot with amazing clarity.

After trying various eyepieces I decided to see if I could take some pictures. Unfortunately, my Canon EOS Rebel XS won't come to focus in the PST's eyepiece tube. I was able to take some afocal shots, though, using the EOS Rebel and my Canon PowerShot A540.

Here are a few processed images, which certainly do NOT do justice to the naked-eye views.

This is a stacked image composed of 23 separate exposures taken with the Canon EOS Rebel XS. There was a lot of atmospheric turbulence, which may explain why the lower-right side of the Sun's disc appears slightly out of place. Note the prominences visible to the lower-left. The dark streaks across the face are probably prominences, as well. Some of the bright patches are plages.

I used a longer exposure time for the frames that were used to compose this image. Some of the features on the face are overexposed, but the relatively dim prominences along the limb are visible. In the future I will attempt to apply some High Dynamic Range techniques to even out the exposure.

This image was composed from several hundred frames from an AVI recorded with my Canon PowerShot A540.


  1. These are cool, Rory! I like my suns yellow, I think, but the others are interesting, too. Perhaps you can catch the Venus transit through this scope and camera!

  2. The colors here are "natural," as I was using color cameras. I borrowed Anjal's monochrome Meade DSI, though, and will be attempting to take some images with it if and when the sky ever clears up. I'll color those yellow just for you! :) All of this is practice, in part, for the Venus Transit. I've scouted out a few locations in the area, and will be scouting for others out of town later in case the weather doesn't cooperate (which I expect it will not). If all goes according to plan I will be imaging the Venus Transit through this scope and my ST80--with a sun filter, of course!