Cookie consent

AstroBin saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing AstroBin without changing the browser settings, you grant us permission to store that information on your device.

I agree
Contains:  PK128-04.1, Sh2-188
Getting plate-solving status, please wait...
Simeis 22 / SH2-188 - The Dolphin Nebula (Bicolor), 


            Frank Breslawski
Powered byPixInsight

Simeis 22 / SH2-188 - The Dolphin Nebula (Bicolor)

Technical card

Dates:Sept. 30, 2018Oct. 4, 2018

Astronomik H-Alpha 6nm CCD: 28x900" -20C bin 1x1
Astronomik OIII 6nm CCD: 24x900" -20C bin 1x1

Integration: 13.0 hours

Darks: ~50

Flats: ~10

Bias: ~200

Avg. Moon age: 22.27 days

Avg. Moon phase: 48.86%

Bortle Dark-Sky Scale: 4.00 job: 2416744

RA center: 1h 30' 4"

DEC center: +58° 28' 44"

Pixel scale: 0.928 arcsec/pixel

Orientation: -178.140 degrees

Field radius: 0.306 degrees

Resolution: 1848x1491

Locations: Home, Bergisches Land, Germany

Data source: Backyard


Simeis 22 (aka Sharpless 188, SH2-188 and the Dolphin Nebula) is an unusual planetary nebula in the galactic disk, approximately 850 light-years away from earth in the northern constellation of Cassiopeia.

I spent around 13 hours for collecting H-Alpha and OIII data for this bicolor. Definitely a nebula for which the term "faint fuzzy" was probably created. ;-) Found some more very interesting facts about Simeies 22:

The expanding gas from SH2-188 has a nearly circular shape, but is much brighter to the southeast (lower left). This is because the rapidly moving central star – at about125 km/s – is s creating a bow shock in that direction in the surrounding interstellar medium. Faint wisps of gas can also be seen in the opposite direction, which will eventually dissipate away. SH2-188 is considered to be one of the best examples of interaction between a planetary nebula with the interstellar medium.



Frank Breslawski
License: Attribution-NonCommercial-ShareAlike Creative Commons

Sky plot

Sky plot


Simeis 22 / SH2-188 - The Dolphin Nebula (Bicolor), 


            Frank Breslawski

In these public groups

Narrowband imaging