NGC 6888 without stars

NGC 6888, the Crescent Nebula in Cygnus (stars removed). Apertura 800mm f/4 newtonian, 28 x 300 exposures with the ZWO ASI071MC cooled to -10C, Optolong dual-band l-eXtreme filter with 7nm bandpasses at Ha and OIII, Sky-Watcher EQ6-R Pro mount, William Optics 32mm/120mm FL guide scope + ZWO ASI290MM guide camera. The Crescent is close to 5000 lightyears away, about 25 lightyears across at its widest point, roughly 237 trillion kilometers wide (150 trillion miles). The dense clouds of oxygen and hydrogen are lit up with the intense radiation of a central star; the whole structure is expanding and accelerating away energetically, very bright against the velvety bed of ionized hydrogen that spans most of the constellation Cygnus. With the stars removed from the image, NGC 6888 almost looks solid instead of a vast bubble of interstellar gas and dust.

Posted May 30, 2023

The Sadr Region (IC 1318) in Hydrogen-alpha

Astronomik 6nm Ha filter, 42 x 240 second subs stacked in DSS. Click the image for the full view

Posted June 7, 2022

North America Nebula (NGC 7000) and the Pelican Nebula (IC 5070, IC 5067)

I spent most of last night's imaging run, about 5.5 hours, on this two-panel mosaic of NGC 7000, the North America Nebula and IC 5070, IC 5067 the Pelican Nebula. NGC7000 and this whole area is one of those deep sky objects with which you can do amazing things in narrowband or broadband color, and turns out beautifully in RGB, bi-color Ha and OIII, even Hydrogen-alpha by itself. For this shot I went with the Hubble Palette in SHO, mapping SII-Ha-OIII to RGB, Sulfur = Red, Hydrogen = Green, Oxygen = Blue. This is why you see aqua and gold standing out in many of the Hubble images. It also affects star color, and you end up with some shade of purple.

Here's an update with the two-panel mosaic of the North America Nebula (NGC 7000) and Pelican Nebula (IC 5070, IC 5068). I fixed the stars and toned down the whole image

Posted June 9, 2019

Veil Nebula--one side of it

Finally a clear-ish night! I spent almost five hours capturing data, most of it after midnight, when the skies cleared noticeably. And I spent the majority of that time on the Eastern Veil Nebula (Caldwell 33). The big bright area is NGC 6992, and all of this comprises one side (east side) of the Veil Nebula, a supernova remnant from a massive star that ended it all around 8,000 years ago. I will come back on another clear night to get the brighter and larger Western Veil. And this nebula is large, roughly 3 degrees in diameter, covering 36 times the area of a full moon. I shot this in Ha and OIII, 22 x 5 minute exposures for each filter, with the WilliamOptics GT81 and ZWO ASI1600MM-Pro mono camera running at -20C. 

Here's the William Optics GT81 and ZWO cameras I'm using for narrowband imaging:

Here's a crop of NGC 6992, 6995, et. al. Eastern Veil Nebula is a supernova remnant in Cygnus, made up of clouds of dust and ionized hydrogen and oxygen.

 

Posted May 25, 2019