Collecting Photons
M52 - NGC 7635 (Bubble Nebula) - SH2 161 - SH2 159 - SH2 157 Cassiopeia
Objects: A complex HII area with several thin dusty lanes and, for the trained eye, even a tiny but remarkable reflection nebula. Finally a strange wisp of nebulosity revealed itself as a peculiar planetary nebula hidden in plain sight south of M52 and east of the bubble: KjPn8.
Constellation: Cassiopeia
Coordinates of field center: 23h 20m +61° 02'
Notes:
The Bubble
nebula itself is recognizable just north of the center of the image. Although
the main illumination source of the area comes from ionized Hydrogen, there are
several structures emitting a sizable OIII contribution. This originates the
nice bluish cast of some areas, notably near the Bubble itself and on the arms
of the SH2-157 complex, south of the Bubble.
Telescope and camera: ASA 10', f 3.6; SBIG STL 11000.
Exposure: Hα 20x16'; R, 12x10'; B 11x10'; G 12x8'. About 11 hrs total.
Date: 4 nights on 5, 9, 10-09-2010 (RGB) and 20-09-2010 (Hα).
Software used: acquisition, CCDsoft, FocusMax, CCDcommander, The Sky VI. Calibration; registration and stacking: CCDstack, Registar; processing: PixInsight, Photoshop CS.
Processing notes: this is a collection of rather bright objects so processing has been pretty straightforward, with the usual emphasis on the protection of star colors. Sadly, the image suffer from a bad collimation of the main mirror that is gradually worsening, but I really have NO time to fix that!
This mosaic is the composition of 4 panels shot with the ASA 10" astrograph. In total 80 16 min subs were composed together, for a total of over 21 hours of exposure. The RGB data will take at least one more year before being completed. Check the high resolution link.
V628 is a rare type of star showing bright emission lines in its spectra. This star is classified as an Orion variable, and it varies in brightness between 10.88 and 11.84 mag. These stars are often associated to bright or dark nebulae, and this is no exception to the rule, being surrounded by a yellow shell that, in spite of being pretty small, shows some interesting features.
The peculiar planetary nebula KjPn8
I was puzzled by a set of tiny filaments that suggested the presence of a shock wave of some sort in the east periphery of the Bubble. My intention of checking the area collided with my perennial lack of time. Then, out from his post of apparently unlimited knowledge of the sky, Sakib Rasool made me noticing that this is the peculiar planetary nebula KjPn8 described in the 70's by Misha Kazarian and Elma Parsamian and well describend in this paper. A fantastic image of this difficult and intriguing subject was shot by the wonder team of the Capella Observatory.
Copyright © 2010 by Gimmi Ratto. (October 13, 2010)
