This is first light with my EdgeHD11 with Hyperstar v4, which compared to my RASA8s can fit in a filter drawer so I can easily change filters. I put in a Baader 4 nm Oiii f/2 filter and aimed at the mysterious blue object I discovered in Cassiopeia about a month ago (
https://www.astrobin.com/cnvp2s/). I then imaged it with RASA8 and an IDAS NBZ dual-band filter (Ha+Oiii) so it was likely a Oiii emitting object, but that filter also let some blue reflection nebulosity through (especially with a light bucket as a RASA). So with the Hyperstar I wanted to make sure it was Oiii the object was emitting. Unforunately I only got 6 x 5 min before clouds moved in. However, for this 11" f/1.9 scope that was enough to reveal a clear Oiii signal, although a bit noisy.
When I posted my RASA image
@Marcel Drechsler enlightened me that the object was registered in Simbad as GSH 122+02-77 "Interstellar Shell" (
http://simbad.cds.unistra.fr/simbad/sim-basic?Ident=GSH+122%2B02-77&submit=SIMBAD+search) with no further info and it has apparently never been imaged. At least we can now be quite sure it is emitting a significant amount of Oiii.
Surprisingly, the Hyperstar v4 was producing good enough corner stars right out of the box (although I bought it second hand) and the small deformations was easily taken care of by BlurXT2, and a tri-Bahtinov mask gave a quite symmetric spike pattern, suggesting no collimation is needed (I have the Hyperstar in a fully screwed in position). That was a big releif.
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