Hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  B369  ·  RW Cep  ·  Sh2-132
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            Gary Imm
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Imaging telescopes or lenses: Takahashi TOA-130NFB

Imaging cameras: ZWO ASI 6200 MM Pro

Mounts: Astro-Physics Mach1GTO

Guiding cameras: ZWO ASI 174 MM Mini

Software: Pixinsight  ·  Main Sequence Software Sequence Generator Pro  ·  Stark Labs PHD2 2.6.3

Filters: Chroma OIII 3nm  ·  Chroma Red 2" unmounted  ·  Chroma Ha 3nm  ·  Chroma Blue 2" unmounted  ·  Chroma Green 2" unmounted

Accessory: ZWO M68 OAG  ·  ZWO EFW 2″X7  ·  Takahashi Flattener TOA-67  ·  Feathertouch Focuser Boss II Electronic Focusing Control

Dates:Nov. 3, 2020Nov. 5, 2020Nov. 6, 2020Nov. 7, 2020

Chroma Blue 2" unmounted: 30x120" (gain: 0.00) -20C bin 1x1
Chroma Green 2" unmounted: 30x120" (gain: 0.00) -20C bin 1x1
Chroma Ha 3nm: 24x300" (gain: 100.00) -20C bin 1x1
Chroma OIII 3nm: 24x300" (gain: 100.00) -20C bin 1x1
Chroma Red 2" unmounted: 30x120" (gain: 0.00) -20C bin 1x1
Chroma SII 3nm: 24x300" (gain: 100.00) -20C bin 1x1

Integration: 9.0 hours

Avg. Moon age: 19.44 days

Avg. Moon phase: 76.03%

Astrometry.net job: 4273092

RA center: 22h 17' 42"

DEC center: +55° 54' 4"

Pixel scale: 0.774 arcsec/pixel

Orientation: 0.402 degrees

Field radius: 1.126 degrees

Resolution: 8432x6228

Locations: Backyard (Mag 20.8 - Bortle 4.5), Onalaska, Texas, United States

Data source: Backyard


This object, nicknamed the Lion Nebula, is a complex large emission nebula located 12,000 light years away in the constellations of Cepheus and Lacerta at a declination of +56 degrees. It has so many interesting features - dark nebulae, bright stars, billowing dust clouds, emission areas, and unusually straight bright regions.

The large orange star on the left is one of the largest known stars in existence, with a diameter larger than the orbit of Jupiter. It is not certain whether this star, the hypergiant RW Cephei, is associated with the nebula or is just in the same field of view.

Two Wolf-Rayet stars, WR 152 and WR 153, are doing most of the ionization of the nebula, despite not being the brightest stars in the nebula. WR 152 is located in the center of the bluish area (OIII) in the Lion's legs, while WR 153 is located in the center of the head of the Lion.

The most fascinating aspect of this image to me is the wide arcing fronts of two expanding gas bubbles. Surprisingly, the Wolf-Rayet stars described above are not the driving mechanism for the bubbles, as they are for other familiar objects such as Thor's Helmet, the Crescent Nebula, and Sh2-308.

One large bubble appears to be driven by the star cluster Berkeley 94, centered just below the bright orange star. The other large bubble encloses two dark nebulae towards the upper right, LDN 1150 and LDN 1154. It seems to me that the latter bubble could be driven by the apparent star cluster just to the left of these dark nebulae, but I could find no evidence in the literature that this grouping of stars is even a cluster.