Unexpected Solar Session

When I got up this morning, I immediately noticed that the sun was shining through our windows.  It was very noticeable because this is not something we see all that often and especially not in the dead of winter when it is typically snowing every single day.  The sky appeared blue so it meant I should attempt a quick solar observing session with a new solar filter.  I had received this new filter a few days previously and was waiting for clear skies to use it for the first time.

The temperature was in the single digits but there was no wind so I figured that the sun would help keep me warm.  I quickly dressed for the frigid outdoors and collected my astronomy gear.  I headed outdoors for a "first light" with this new filter.

As expected with these sort of things, this session didn't go as planned.  It is often difficult to figure out the focus point for a new piece of equipment so I expected to have to play around with different configurations.  Needless to say, I had difficulty finding focus and that wasted quite a bit of time.  

My view was completely black which I found quite odd.  Typically, you should be able to still see a very unfocused bright sun in your view if you have the wrong focus point but I was seeing absolutely nothing.  Since I had never used this particular filter before, I couldn't tell if my focus was very, very far out of range or if there was some other issue.  When faced with problems, you should always start troubleshooting with the simple solutions so I continued to try different configurations to find the focus point.

I added extensions into the optical path but that didn't seem to help at all.  Then I went to the other extreme and I removed all the extension tubes as well as my diagonal to see if that would help.  This time, I was able to see some light so that was good news.  Unfortunately, I still couldn't focus the sun.  I was definitely out of focus range in this configuration but actually seeing the unfocused sun was good news.  This meant that light was getting through the filter. 

All this reconfiguring, screwing and unscrewing of metal parts was beginning to affect my fingers in this frigid environment.  I was wearing fingerless wool gloves which kept my hands as warm possible while still allowing me to easily handle delicate optics but touching freezing metal with bare fingertips could only continue for so long without consequences.  I knew my time outdoors was limited due to the cold and I was now getting very close to that limit.

Since I was having no success at the two extremes of configurations, I then put the diagonal back into the optical path but spent more time trying to point right at the sun.  It didn't make sense that I couldn't see any light whatsoever.  At this point, since my view was again black, I pulled the eyepiece out of the new filter and peered down into the filter with no eyepiece in place. I was seeing no light which was very strange and very frustrating.  

I was beginning to realize that I simply might be having difficulty actually pointing the telescope at the sun perfectly.  This eyepiece filter magnifies the view by 4.3x so that makes for a very narrow view.  Narrow views make pointing the telescope very difficult because the accuracy needs to be far more precise.  This narrow view makes it far more difficult to find objects.  It is like trying to find something through a straw rather than through a cardboard toilet paper roll.  

I eventually found the sun again while looking down into the top end of the filter without an eyepiece.  I then carefully placed the eyepiece back into the filter.  I immediately noticed that my eye needed to be placed just right to see the sun.  Eye placement over the eyepiece was probably one of the reasons why I was having difficulty finding the sun up until now.  I carefully focused on the limb of the sun and I immediately noticed a bunch of very clearly defined prominences which was quite a pleasant surprise.

These prominences look like flames reaching out thousands of miles from the edge of the sun.  This impressive phenomenon is actually plasma erupting along magnetic field lines in the form of large fiery arches and loops.  Most of these prominences were small but very visible.  Some of them were bright, large and very noticeable though.  This was a really nice view!

On the surface of the sun where you can typically see a lot of fiery detail of the chromosphere with this type of filter, however, I really wasn't seeing a whole lot of detail.  I could faintly see some mottling of the surface but it was very, very faint.  There were two filaments visible but it was time to start adjusting the filter to get it on band at the hydrogen alpha wavelength which would allow me to see more detail.

Adjusting this particular solar filter to get it on band is a bit time consuming and tedious.  For each notch you turn the tuning knob, you must wait 10 minutes for the filter to heat up or cool down.  There are many notches in this tuning knob so tuning could require an hour or more to someone new to this type of filter like me.  I knew I couldn't stay out in single digits for another ten minutes nevermind an hour or more.

At this point, I had been out in the single digit temperature for about a half hour so I was beginning to shiver and my fingers were far too cold.  I knew I needed to warm up a bit before doing anything else to keep from developing frostbitten fingers again.  I was set up on the side of the road at the end of our driveway because this is the only place to get an unobstructed view of the sun early in the morning this time of year.  I wasn't going to leave my telescope at the road so I had to carry the whole telescope and mount back to the house on my way indoors.  This in itself was a bit of a challenge since underneath the fresh three inches of snow was slick ice.  

I spent a few minutes indoors to warm up.  While warming up, I gathered a few other eyepieces to try when I went back outside.  I wasn't all that happy with the field of view with any of the eyepieces I tried.  I mean the views were good but I was hoping to get a whole view of the full disk of the sun but the sun was barely fitting inside the view.  If I was using a tracking mount this might not be much of a problem but, when using a manual mount as I was at that moment, it was impossible to keep the full disk of the sun in the view for more than a few very short seconds.  I didn't use a tracking mount on this particular day because I was trying to make the session as short as possible due to the frigid temperatures. Setting up and aligning a tracking mount would require more time outdoors than I could handle in this cold so I opted for a manual mount so I could quickly test this new filter.

The image to the left shows this hydrogen alpha solar filter.  The filter is the red part with the knob and LED light on it and the black tapered part directly below the red part.  This rather unique filter slides into the diagonal and then you place an eyepiece into the eyepiece holder clamp at the top of the filter.  I power this filter with a small 5 volt battery pack (one that we use as a portable charger for when we are on the road) which seems to be working very well.  

Naturally, as luck would have it, the clear skies were very short-lived so I didn't really have enough time to fully run this new filter through its paces.  Today, although it is significantly warmer outside (in the 40s), it is completely overcast out there so there is no viewing the sun today.  

I made a bit of progress in this session but I still need to have more time with this filter.  I'm looking forward to warmer days and clearer skies!