Hemisphere:  Northern  ·  Constellation: Gemini (Gem)  ·  Contains:  1 Gem  ·  10 Gem  ·  11 Gem  ·  11.99  ·  12 Gem  ·  13 mu. Gem  ·  13.62  ·  139 Tau  ·  141 Tau  ·  15 Gem  ·  16 Gem  ·  18 nu. Gem  ·  2 Gem  ·  3 Gem  ·  389 Industria  ·  4 Gem  ·  412 Elisabetha  ·  5 Gem  ·  6 BU Gem  ·  62 chi02 Ori  ·  64 Ori  ·  68 Ori  ·  7 eta Gem  ·  71 Ori  ·  8 Gem  ·  9 Gem  ·  B227  ·  Gem A  ·  IC 443  ·  IC2156  ·  And 34 more.
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Monkeyhead Nebula, Jellyfish Nebula, and M35 at 85 mm in HOO, 



    
        

            JDJ
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Monkeyhead Nebula, Jellyfish Nebula, and M35 at 85 mm in HOO

Getting plate-solving status, please wait...
Monkeyhead Nebula, Jellyfish Nebula, and M35 at 85 mm in HOO, 



    
        

            JDJ
Powered byPixInsight

Monkeyhead Nebula, Jellyfish Nebula, and M35 at 85 mm in HOO

Imaging telescopes or lenses: Rokinon 85 mm f/1.4

Imaging cameras: Nikon D5300 Full Spectrum Modified

Mounts: Celestron AVX Mount

Guiding telescopes or lenses: Agena Astro Guidescope, 50mm f/3.8, 190 mm focal length

Guiding cameras: ZWO ASI120MC-S

Software: PixInsight 1.8

Filters: STC Astro Duo-Narrowband filter (Nikon aps-c clip)


Dates:Feb. 8, 2020

Frames:STC Astro Duo-Narrowband filter (Nikon aps-c clip): 75x60" (1h 15') ISO800

Integration: 1h 15'

Darks: ~40

Flats: ~15

Flat darks: ~15

Bias: ~20

Avg. Moon age: 13.85 days

Avg. Moon phase: 99.06%


Astrometry.net job: 3334893

RA center: 6h 14' 20"

DEC center: +22° 37' 24"

Pixel scale: 9.381 arcsec/pixel

Orientation: -2.697 degrees

Field radius: 5.479 degrees


Resolution: 2735x3195

Locations: Home, Silver Spring, Maryland, United States

Data source: Backyard

Description

This wide field image of the region around the Monkeyhead Nebula (IC2159), Jellyfish Nebula (IC443), and open cluster M35 was captured on the night of February 8, 2020 using a short telephoto lens and dual narrowband filter. This was the second target during an imaging session exploring use of short exposures at high iso (relative to my usual exposure setting). For more details and the first image, see:

My conclusion was to stick with my typical longer exposures and low iso.

Imaged with 85mm/F1.4 Rokinon at F/2, STC Duo Narrowband Clip Filter, and full spectrum modified Nikon D5300.

Total integration time was ~1 hours using 75 subs at ISO 800 x 60 sec. Pre-processed using PixInsight Batch Pre-Processing (BPP) script. Images calibrated using darks, bias, and flats. Instead of separating out the R, G, and B channels and processing the narrowband results separately, I just processed this as a standard RGB image (one of the benefits of using a dual narrowband filter with a OSC DSLR). Post-processed in PixInsight: Cropped, gradient removal with ABE, MLT for noise reduction, stretched in two stages, stage 1 stretch using histogram transformation with starmask generaated using starnet++ (to start to bring out the nebulocity), stage 2 stretch using masked stretch, Curves Transformation, TGVDenoise for noise reduction, HDR transform, Local histogram transform, morphological transform to shrink stars.

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