2022 Michael A. Siniscalchi
Home

What's New

About

Gallery

Odds n Ends
Contact

      SH2-155
        Diffuse Nebula in Cepheus
           RA:22h 56m 47s  Dec: +62 36' 59" Distance - ~2,707 ly Size 50'x30'

Location & Date
Backyard, Abbott Observatory- Long Island, NY,  July & August 2022
Telescope
TMB130SS  910mm F/7 APO, Moonlite focuser, Losmandy G11 Gemini
Image scale 1.54 arcsec/pixel
Camera
SBIG ST-10XME
Baader Ha SII OIII  5nm  filters
CCD temp -15C
Exposures
Ha-18x5m  OIII-12x10m   SII-18x5m  Bin 1x1
for each of the 4 panels
Planning & Acquisition
Sequence Generator Pro Mosaic Tool - 4 panel Mosaic

Processing
CCDStack -  Calibration, Debloom
Astro Pixel Processor - frame processing and mosaic assembly, Ha SII OIII combine
Adobe PS -  Ha SII OIII processing, JPEG conversion
RC-Astro Star XTerminator & NoiseXTerminator
This is a 4-panel mosaic using the HST pallette where Ha=green, OIII=blue and SII=red
Wikipedia-

Sh2-155 (also designated Caldwell 9, Sharpless 155 or S155) is a diffuse nebula in the constellation Cepheus, within a larger nebula complex containing emission, reflection, and dark nebulosity. It is widely known as the Cave Nebula, though that name was applied earlier to Ced 201, a different nebula in Cepheus. Sh2-155 is an ionized H II region with ongoing star formation activity, at an estimated distance of 725 parsecs (2400 light-years) from Earth.

Sh2-155 was first noted as a galactic emission nebula in 1959 in the extended second edition of the Sharpless catalogue, being a part of the much larger Cep OB3 Association. Although Sh2-155 is relatively faint for amateur observation, some of its structure may be seen visually through a moderately sized telescope under dark skies.

Sh2-155 lies at the edge of the Cepheus B cloud (part of the Cepheus molecular cloud), and is ionized by young stars from the Cep OB3 association. It has been suggested that radiation from the hot O-type star HD 217086 is compressing the region, triggering the formation of a new generation of stars. A study of the region's young stellar objects by the Chandra X-ray Observatory and Spitzer Space Telescope shows a progression of stellar ages in front of the cloud, supporting the hypothesis of triggered star-formation.

Click on image for half size
Clik here for full size
SH2-155 position shown relative to our location (Sun) in the Milky Way Galaxy
Galatic Longitude: 110.2
Galatic Latitude: 2.6
Distance from Galatic Plane:180 ly above the galatic plane

Above image and info provided by Our Galaxy 3D Atlas application and used with permission by Otherwise
Initial stretch of 1 1/2 hours for each of the 4 panels Hydrogen (Ha) data

Initial stretch of 1 1/2 hours for each of the 4 panels Sulphur (SII) data

Initial stretch of 2 hours for each of the 4 panels Oxygenn (OIII) data

Initial combine of Ha SII & OIII frames using the HST palette in Astro Pixel Processor. This was then imported into Photoshop for additional processing.