SH2-162 (NGC 7635, Bubble Nebula)
SH2-162 (also known as NGC 7635 or Bubble Nebula) is an emission nebula in constellation Cassiopeia. The region is ionized by the hot young O-type star BD +60 2522 which lies at a distance of about 9800 ly (light years) from Earth (Gaia DR3 data). The stellar wind of this star interacts with the matter of a surrounding molecular cloud and forms a bubble. Its apparent diameter is about about 200" (arcseconds), its true diameter is about 9.5 ly. The diameter of the ionized region of the molecular cloud is about 120 ly.
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BD +60 2522, the ionizing star which stellar wind forms the bubble, is the brighter star in the bubble next to the saturated area.
Image data
| FOV: | 0.67° × 0.51° (full view) | ||||||||||
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| Date: | 2018-2021 | ||||||||||
| Location: | Pulsnitz, Germany | ||||||||||
| Instrument: | 400mm Newton at f=1520mm | ||||||||||
| Camera Sensor: | Panasonic MN34230 | ||||||||||
| Orientation: | North is up (approximately) | ||||||||||
| Scale: | 0.8 arcsec/pixel (at full resolution) | ||||||||||
| Total exposure times: |
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Image processing
All image processing steps are deterministic, i.e. there was no manual retouching or any other kind of non-reproducible adjustment. The software which was used can be downloaded here.Image processing steps where:
- Bias correction, photon counting
- Dark current subtraction, flatfield correction, noise estimation
- Alignment and brightness calibration using stars from reference image
- Stacking with masking unlikely values and background correction
- Extracting stars from the emission line images using information from continuum images
- Denoising and deconvolution both components (stars and residual)
- RGB-composition
- Dynamic range compression using non-linear high-pass filter
- Tonal curve correction
