Simeis 22 (Sh2-188 or Shrimp Nebula), is an unusual planetary nebula located in the constellation Cassiopeia. The nebula is nearly circular in shape but is much brighter to the lower left as a result of the central star moving rapidly in that direction. This is creating a bow shock as the expanding gas from the nebula collides with ambient gas of the interstellar medium while leaving faint trailing gases in it's wake.
The emission nebula was discovered in the early 1950s by the Russian astronomers Grigory Abramovich Shajn and Vera Fedorovna Gaze at the Simeis Observatory on the Crimean Peninsula. The American astronomer Stewart Sharpless found the same emission nebula while searching the photo plates of the Palomar Observatory Sky Survey that were made using the 48 inch Schmidt telescope. Sharpless cataloged it in 1959 as Sh2 - 188.
Sh2 -188 is estimated to be about 22,500 years old and is about 800 lightyears from Earth.

Image Capture Details:

20x900s each Ha and Sii. Processed in HSS plus 6x300s each RGB stars.
Telescope - PlaneWave 12.5" CDK
Mount - iOptron CEM120EC2
Camera - ZWO ASI2600MM
RA 01hrs 30' 32"
DEC +58degrees 25' 28"
Position Angle (CCW) - 90 degrees
Location - Calgary Alberta
Date - October 2024
Constellation - Cassiopeia
Distance - 800 lightyears

Processed in ImagesPlus, PixInsight and PhotoShop