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NGC 4038 & 4039, Antennae Galaxies, OSC (UHC-S), 5-6 Apr 2016

Technical card

Resolution: 781x622

Dates: April 6, 2016

Frames: 29x600"

Integration: 4.8 hours

Avg. Moon age: 27.82 days

Avg. Moon phase: 3.28% job: 1030377

RA center: 180.481 degrees

DEC center: -18.873 degrees

Pixel scale: 1.869 arcsec/pixel

Orientation: 91.790 degrees

Field radius: 0.259 degrees

Locations: Mapleton Lateral Observatory, Mapleton, Utah, United States


Excellent sky conditions. Did some experimenting with my USB setup prior to starting the session, and found my older hub (the one that was out during the "Sprinkler Disaster") is in the process of giving up the ghost (it kept refusing to connect to things). So I ran the whole session off the newer hub (but I anticipate getting a better USB 3.0 hub, with better power specs and asynchronous capabilities, today). Initially had problems plate solving, so I thought "Here we go again, I can't plate solve with the coma corrector installed." However, this time I knew I had the scale and aspect ratio correct, and realized the initial goto was just too far off. Once I used the Telrad to find and synch on a bright star, all was well. Once again did a successful unattended meridian flip. My goal was to do a better job of picking up the tidal tails of NGC 4038, and that worked out nicely. I still don't like the colors I'm getting, so I desaturated them a bit.

In the revision, I got on a better monitor and could see the nasty gradient background, so I used levels to reset the midpoint and darkened a bit.

Date: 5-6 Apr 2016
Subject: NGC 4038 & 4039, Antennae Galaxies
Scope: AT8IN + High Point Scientific Coma Corrector
Filter: Baader Planetarium UHC-S
Mount: EQ-6 (EQMOD) + PEC
Guiding: Orion ST-80 + Antares 0.5x focal reducer + DSI Ic + PHD (Win 7 ASCOM)
Camera: DSI IIc, no chiller CCD dropping from 10 °C to about 0.5 °C
Acquisition: Sequence Generator Pro with Nebulosity 4.0.4 ASCOM camera driver
Exposure: 29x600 s
Stacking: Neb 4, bad pixel map, bias included, 40 flats, match histograms, trans+rot align, Deep Sky Stacker 1.5σ κ-σ stack without drizzle.
Processing: StarTools 1.4.305: Crop; Wipe; Develop: 87.99%; HDR:Optimize; Color:Scientific, 200% saturation, red bias reduce at 1.32; Deconvolute: 2.2 pix; Track: Smoothness 87%, 4.5 pix; Magic, shrink 2 pix. Photoshop CS6 + Astronomy Tools: Deep space noise reduction; Space noise reduction; Increase star color; Levels; Curves; Liquify/pucker on brighter stars; Less crunchy more fuzzy; Layer masked unsharp mask 3.0 pix just for interior of galaxy; Astroframe.



David Dearden

Sky plot

Sky plot


NGC 4038 & 4039, Antennae Galaxies, OSC (UHC-S), 5-6 Apr 2016, David Dearden