Bubble nebula - h-alpha (work in progress?)

[vlaiv]

Here is 4 (ish) hours of Bubble nebula in h-alpha.

Conditions rather good, seeing was excellent - I even managed 0.38" RMS total at times with Heq5 - unheard of with this mount (it changed mostly between 0.6" and 0.48" during the night). There was sort of temperature inversion - which meant high pressure, not very good transparency (hazy skies) and ultimately dew on secondary - also unheard of for RC scopes (secondary is really well baffled, and I've never had it dew up before).  So last 1.5h, rig was running at 50%

64x4 minute, ASI1600, RC8".

TTLR normalization (my invention - basically linear fit with first order tilt for LP gradients), Sigma clip stacking (due to couple of satellites and one airplane in FOV). Basic stretch in Gimp and very light denoise (inverse mask blended).

Presented here at ~ 1"/pixel

Hopefully, nice weather remains until the end of the week and I'll try to capture OIII and SII on this target to complete my first SHO (or maybe different palette rendition?) image.

[peter shah]

beautiful detail