MiniSHG and Baader 7nm Ha filter

[Merlin66]

The attached screen shot shows a few things:
1. The Baader 7nm Ha filter actually has peak transmission at 6580A.
2. The movements in the solar surface are clearly seen as "wiggles" in all the absorption lines.


The measured resolution R=33529 and the dispersion 0.0635 A/pixel match up pretty well with the SimSpec results for the MiniSHG.

[robin_astro]

Hi Ken,

What's causing emission peaks round the sharp absorption lines ? Is this some sort of sharpening/compression artifact?

Or a diffraction effect off the edge of a very narrow slit perhaps?

Robin

Edited September 28, 2021 by robin_astro
added possible slit diffraction effect

[robin_astro]

13 hours ago, Merlin66 said:

2. The movements in the solar surface are clearly seen as "wiggles" in all the absorption lines.

The same wiggles are also seen in the Telluric H2O lines from our own atmosphere so cannot be solar in origin.  See the comparison with a high resolution  annotated professional spectrum

Cheers

Robin

 

[Merlin66]

Robin,

The artefacts come from sharpening.

I've extracted a few frames from a full solar disk, 9 sec scan, which show the "normal" cropped H alpha spectrum used to re-construct the SHG image. ( Cropped to 1150 x 170 for the GIF)

You can see the "wiggles" in the Ha line caused by the surface features and a couple of sunspots tracking across.

The wiggles do impact on all lines (?) but I accept the telluric should only show the seeing.

The solar image shows the results from this full scan.

Ken