The first clear day we have had in months. I have had a previous test session on a 'nice' day but trying to dodge clouds made some of the results a little uncertain. On this day, I spent almost 5 hours experimenting. The Sol'Ex was attached to a 60mm F4 finder/guide scope piggy backed onto my 80mm refractor attached to a EQ5 mount, driven in RA only. Camera is a ZWO asi138MM mono camera. The telescope was stopped down to 36mm aperture and a 90% neutral density filter fitted.
I have two challenges to overcome, one is focussing the instrument on the edge of the spectrum, essentially, the edge of the sun through the slit. Over half of the scans that I took were simply not sharp enough.
The second is learning to navigate my way through the hundreds of lines that are presented, that will take some time. It is not helped as the Sol'Ex adjustment is quite coarse, I need to develop a fine adjustment mechanism, possibly geared or micrometer based.
Image capture using SharpCap 4.1 and subsequently processed (immediately after capture) using jSolex.
Nonetheless, I am very pleased with these results.
Hydrogen Alpha
By far and away, the easiest line to find is Ha at the red end of the spectrum. The line is very broad, probably due to doppler shift and the fact that there is so much of it.
The resolution is about 0.4 Angstrom. For a 240mm FL telescope with an aperture of only 36mm, I think this image is quite remarkable.
The dopplergram has not worked as well as I hoped. I think that the banding is caused because I selected too much of the spectrum but I am not absolutely sure.
One nice feature of the software is that the image of the Sun has an overlay grid which should be accurate providing the Sol'Ex is properly aligned.
Hydrogen Beta
Another fairly easy line to find line in the blue part of the spectrum.
Again, banding is visible. Chromosphere features are not as clearly defined as the Ha, sunspots are more clearly visible. Scan was slightly over exposed.
Calcium H
At the deep violet end of the spectrum. The image on the screen is quite dark and a fair amount of gain was needed to get the short exposure needed to achieve the high frame capture rate.
This and the fairly adjacent Ca K line are difficult to distinguish and I am not absolutely certain I have get these right. This certainly shows the active regions, and some sunspot detail is also marginally visible.
Calcium K
This was the final set of images that I am presenting from this session. Only slight differences from the Ca H image above. Sunspots are less visble. Note the slight cropping because I hadn't centralised the image on the screen.
The two images look very similar, however, I hadn't altered the gain on the Ca K image which, because it is further in the deep violet part of the spectrum appears a little darker. More testing required!
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