NGC6357 in Narrowband
07-Jun-2016
NGC 6357 is a diffuse nebula in the constellation Scorpius. The nebula contains many proto-stars shielded by dark disks of gas, and young stars wrapped in expanding gases. It is also known as the Lobster Nebula. Presented is a narrowband SHO photograph in the Hubble Space Telescope palette.
Image:
- 18x 900s 6nm H-alpha bin2x2 + 20 flat + 50x dark + 120x bias
- 26x 510s 12nm SII bin2x2 + 12 flat + 50x dark + 120x bias
- 22x 480s 12nm OII bin2x2 + 25 flat + 50x dark + 120x bias
- 25x 48s Red bin3x3 + 15 flat + 50x dark + 120x bias
- 21x 48s Green bin3x3 + 15 flat + 50x dark + 120x bias
- 26x 48s Blue bin3x3 + 15 flat + 50x dark + 120x bias
Total exposure 12 hours 5 minutes.
Hardware:
- Celestron EdgeHD 1100
- SkyWatcher EQ8 Pro Mount
- Celestron 0.7x EdgeHD focal reducer
- QSI 683-ws Camera @ -15°C
- Astronomik Typ 2c RGB filters, 6nm Ha, 12nm SII, 12nm OIII
- Starlight Xpress Lodestar X2 Autoguider
- Innovations Foresight On Axis Guider
- Starlight Xpress Adaptive Optics
- Starlight Instruments Focus Boss II
Location:
- Green zone in Brisbane, Australia. (Bortle 7)
- Imaged over 4 nights.
Software:
- Planning & camera alignment with Aladin 9
- Captured with AstroArt 6
- Guiding with PHD2 + PHD_Dither
- FocusLock live focusser
- CCDInspector: Image analysis & rejection
- CCDStack 2+: Calibrate, align, stack, deconvolution.
- Photoshop CC: Reduce noise, high pass filter, minimum filter, shadows/highlights, levels, curves, combine HSO as RGB, superimpose RGB stars using Ha as lumininosity channel.
Bonus:
Compare this new image to one I took almost a year ago of the same object to see my progress: