SH2-101 (also known as Tulip Nebula) is an emission nebula in constellation Cygnus. It is assumed that the nebula is ionized by the Cygnus OB3 association which lies at a distance of about 6500 light-years (from Earth), see . One famous member of this association is HDE 226868 which
forms a binary system with the suspected black hole Cygnus X-1.
0.67° × 0.5°
400mm Newton at f=1520mm
North is up (approximately)
0.8 arcsec/pixel (at full resolution)
Total exposure times:
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)
Dynamic range compression using non-linear high-pass filter