NGC 2736 - The Pencil Nebula
02-Feb-2017
NGC 2736, known as the Pencil Nebula is a part of the supernova remnants from the Vela pulsar, 815 light years away.
This image is a narrowband presentation of hydrogen, and oxygen emission lines, mapped to red and blue respectively, with the green channel synthesized as Ha x OIII. Stars colours were captured with shorter exposures using RGB filters.
Image:
- 31x 900s 6nm H-alpha + 10 flat + 50x dark + 120x bias
- 30x 900s 6nm OIII + 15 flat + 50x dark + 120x bias
- 18x 40s + 15x 20s Red + 10 flat + 50x dark + 120x bias
- 18x 40s + 16x 20s Green + 10 flat + 50x dark + 120x bias
- 19x 40s + 19x 20s Blue + 10 flat + 50x dark + 120x bias
Total exposure 16 hours 8 minutes.
Hardware:
- Skywatcher Black Diamond ED120
- SkyWatcher EQ8 Pro Mount
- QSI 683-ws Camera @ -15°C
- Astronomik 6nm Ha, 12nm SII, 12nm OIII, typ 2c RGB filters
- Starlight Xpress Lodestar X2 Autoguider
- Innovations Foresight On Axis Guider
- Starlight Instruments Focus Boss II
Location:
- Orange zone in Brisbane, Australia. (Bortle 7)
- Imaged over 6 nights, high temperatures & humidity, new moon.
Software:
- Planning & camera alignment with Aladin 9
- Captured with AstroArt 6
- Guiding with PHD2 + PHD_Dither
- FocusLock live focusing
- CCDInspector: Image analysis & rejection
- CCDStack 2+: Calibrate, align, stack, combine RGB.
- Photoshop CC: Reduce noise, high pass filter, gradient removal, levels, curves, color map, saturation.