Hydrogen alpha, beta, gamma and delta SHG images -- 9 June

[thesmiths]

Using the spectral line maps that I made yesterday viewtopic.php?t=41126, I was able today to image four of the Hydrogen Balmer lines in a single session using a 80ED 600mm focal length telescope with my foamboard SHG. This setup still needs some tuning up so the top and bottom edges of the solar disk are not completely sharp. Nevertheless, this is a slightly easier instrument to rapidly and accurately tune the wavelength vs my higher resolution (and lower distortion) dovetail SHG (with 106mm aperture APO triplet refractor).

I started off with H-gamma (which somehow turned out the worse), followed by H-beta, H-delta and finally H-alpha. I scanned in RA and had some mount scanning problems, which meant I lost around half the scans in one direction. The image below shows the four wavelengths in a mosaic (all the images are rotated to bring the solar equator approximately horizontal). The Hydrogen beta, gamma and delta SHG images notably look quite similar. Beta shows prominences more strongly than gamma and delta. The data presented here is reduced by 50% from the original size but still benefits from opening in a new tab to see at higher resolution.

Hydrogen SHG images:
Alpha (656.3 nm) top left
Beta (486.1 nm) top right
Gamma (434.0 nm) bottom right
Delta (410.2 nm) bottom left

090623-Ha-Hb-Hg-Hd-80mm.jpg (1.95 MiB) Viewed 1317 times

[thesmiths]

I attach the H-alpha and H-beta as individual images (50% reduction, cropped slightly).

090623-Ha-80mm-stack7-crop.jpg (406.78 KiB) Viewed 1300 times

090623-Hb-80mm-stack8-crop.jpg (414.49 KiB) Viewed 1300 times

[ChrisHalpha2017]

Fantastic results !! thats amazing !

[thesmiths]

I am intrigued by the H-delta, as I have not seen an image in this line before. I decided to make a GIF to show the differences between the delta and beta lines.

H-beta and H-delta SHG images

090623-Hb-Hd-80mm.gif (1.59 MiB) Viewed 1287 times

[KMH]

Fascinating! I guess it makes sense that the visual differences become progressively less in correlation with the wavelengths getting progressively closer together.

Kevin

[rsfoto]

Hi,

Well done

[highfnum]

as you go up in energy level some features start to fade away
makes sense

[Alun_H]

Great set of images Douglas. Was going to give these lines a go myself today but my EQ6 refused to scan properly right from the outset.

Alun

[thesmiths]

Christian Buil looked at these images and made the interesting suggestion that if you look away from the centre of the H-alpha line, you should see images that look like H-beta, H-gamma, H-delta. I found this intriguing. I therefore took a series of pixel shifted images around the H-alpha line and found at 11 pixels, the image does resemble the other Balmer lines. I blended the +11 and -11 pixel shifted H-alpha image and put result side by side with the H-gamma stacked image. There is a strong similarity between the two. Using SIMSPEC SHG, I calculated the dispersion of the spectrometer I used is 0.052 angstrom/pixel. So the blended 11 pixel shift image above corresponds to +/- 0.57 angstrom.

Left: H-gamma, stack of 6 frames
Right: H-alpha, blend of +11 and -11 pixel shift

090623-Hg-stack6-Ha-121910-shift11-blend.jpg (505.34 KiB) Viewed 1189 times

[Montana]

Douglas!!! I could make you SPOD every day for pushing the boundaries of solar imaging

Alexandra