M1 - The Crab Nebula in synthetic RGB
The Crab Nebula is a supernova remnant that has an apparent magnitude of 8.4 and lies about 6,500 light-years away in the constellation Taurus. Corresponding to a bright supernova recorded by Arab, Chinese and Japanese astronomers in 1054, this nebula was observed by John Bevis in 1731 and was recorded as the first Messier object catalogued in 1758. Some catalogue designations for the Crab Nebula are M1 (Messier 1), NGC 1952, Taurus A, Sharpless 244 (Sh2-244) and LBN 833.
This image was created using narrowband data where the emission lines were assigned to the color channels to mimic natural colors. We used the technique outlined by Richard Crisp where 100% H-alpha + 33% SII = red, 100% OIII = green, & 100% OIII + 33% H-alpha = blue.
Click here to see the H-alpha image.
Click here to see the OIII image.
Click here to see the SII image.
- Telescope: Celestron 8” EdgeHD @ f/10
- Accessories: Dew control by Dew Buster
- Mount: Takahashi EM-200 Temma2
- Camera: QSI583wsg CCD @ -10.0C
- Guiding: Starlight Xpress Lodestar via PHD
- Filters: Astrodon 5nm Ha, OIII, SII
- Exposure: 8 x 30min.(Ha); 8 x 30min.(OIII); 8 x 30min.(SII); all frames binned 1x1
- Acquisition: ImagesPlus Camera Control v5.0
- Processing: Calibration, DDP in ImagesPlus 5.0; Registration in RegiStar
- Post-processing: ImagesPlus 5.0; Adobe Photoshop CS5; Gradient Xterminator, Noise Ninja
- Date(s): November 25, 2012; December 11, 12, 13, 2012
- Temperature (begin - end): N1:41.7ºF – 36.5ºF; N2:31.5ºF – 26.1ºF; N3:37.9ºF – 28.8ºF; N4:37.0ºF – 30.6ºF
- Capture conditions: N1 - transparency: Above Avg 4/5; seeing: Poor 2/5; N2 - transparency: Above Avg 4/5; seeing: Avg 3/5; N3 - transparency: Above avg 4/5; seeing: Avg 3/5; N4 - transparency: Above Avg 4/5; seeing: Excellent 5/5
- Location: Hendersonville, TN, USA