Scope:
AT60EDP at f/5;
Location: DAA Observatory, Shelter
Valley, CA;
Dates:
17, 18, 23, 26 August, 15 September, 2025;
Camera:
ASI2600MM (Astronomik type 2c LRGB, 6 nm Ha filters);
Exposure:
22.83 hrs
Lum -
124 x 3.5 min (gain-101 1x1)
RGB -
40 x 2 min (gain-101 1x1) each RGB exposures.,
Ha - 138
x 5 min (gain-160 1x1)
Processing:
Data
Collection - N.I.N.A. Sequencer (as FITs). Sub-frame calibration -
Pixinsight (WBPP).
Sub-frame registration and integration (Average combine
- Linear clipping), Lum, Ha, OIII (2x drizzle) - PixInsight (WBPP).
Noise reduction - NoiseXTerminator - PixInsight.
Non-linear
stretching, normalization and gradient removal - PixInsight.
Photometric
RGB calibration (SPCC) - PixInsight.
Deconvolution
of Lum, Ha stacks and RGB combine - BlurXTerminator.
Generation
of starless nebulosity Lum, Ha, and RGB images for later processing
- StarXTerminator.
Curves,
Levels, RGB combine - PixInsight. RGB Stars and starless combine -
PixInsight.
Final
finishing - Affinity Photo.
Annotation
- PixInsight, Aladin (Simbad ), and Affinity Photo.
This
image is a Ha screened LRGB starless
construction - with RGB stars added. Image processed at 12496 x 8352 resolution.
Final
Image size is approximately 4726 x 7064.
Description:
North is left in this image. The
upper part of this image is the Fire and Ice contrast of Sh2-133 (red
emission arc) and LBN 472 (blue reflection nebula).
The lower part of
the image has NGC 7129 - the Cosmic Rosebud IR cluster and nebula, NGC 7142
- the very old open star cluster, and NGC 7139 - planetary nebula.
The full field is
a contrast of distance in Milky Way galactic objects.
The bright stars are, of course, foreground objects - generally less than 1,000 light years.
LBN 472 (ICE) and illuminating star (6 Cep) are also foreground objects at about
1,316 light years. Sh2-133 as well as much of the red hydrogen emission (Fire)
are around 2,600 light years. This emission is generally energized by the
Cep OB2 star association. This is part of the much larger Cepheus Bubble believed
to be an ancient SNR remnant. Familiar targets Sh2-129, 131, 134, 140 are
apparently part of the Bubble along with Sh2-133.
Further
distant in the lower part of the image is NGC 7129 - "The Cosmic
Rosebud". This is a star forming region at about 3,300 light years. NGC
7129 is also an IR cluster associated with the nebula (not visible in visible
wavelengths). Its dust and ISM are part of the larger TGU H645 P2 cloud whose
extent cover about the lower left quadrant of the image.
The planetary
nebula, NGC 7139, is harder to place at accurate distance, but is
estimated from 4,000 to 7,800 light years. Finally there is the NGC 7142
open cluster which lies behind the TGU 645 P2 cloud that causes some extinction
of the cluster.
