SH2-170

SH2-170 is a faint emission nebula in constellation Cassiopeia. The ionization source is "LS I +64 11", the bright star in the center. Parallax measurements for this star are not precise and lead to a distance between 5100 light years and 6400 light years (Gaia DR3).

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SH2-170 in false colors (SHO) — This image is a false color composite where [SII] is mapped to red, H-alpha is mapped to green and [OIII] is mapped to blue. Stars are partially subtracted using continuum images.

SH2-170 in false colors (OHS) — Same view as above, but [SII] and [OIII] are swapped in order to show more details of the oxygen structures (reddish).

Image data

FOV:

0.56° × 0.5° (full view)

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:

H-alpha (3nm):	8.1 h
[OIII] (3nm):	12.1 h
[SII] (3nm):	14.1 h
NIR:	0.7 h
Blue:	0.6 h

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