Casitas de Gila, Gila, NM
April 9 - 13, 2021

Reprocessed 02/20/2023.

Original:

During my April 2021 astrophotography trip to Casitas de Gila, Gila, New Mexico, a prime target in my imaging plan was the Antennae galaxies in the constellation Corvus.  Conditions were challenging with intermittent clouds, variable transparency and some nights with less average seeing as the Jet Stream raged overhead.  These colliding galaxies were imaged over four nights using Luminance, Red, Green and Blue filters.  Many subframes were discarded as conditions degraded image quality.

Reprocessed:

I continued my effort to reprocess most of the image data sets that had flaws and issues using new PixInsight tools and an improved workflow.  Again, Russ Croman’s XTerminator tools, and PixInsight’s WBPP, SPCC and GHS process tools made a significant difference in improving the imaging and simplifying the workflow.

Description:

The Antennae are about 63 Mly away (they may be closer per recent astronomical studies).  The light reaching us now was emitted shortly after the dinosaurs went extinct and our rodent ancestors began to proliferate and evolve rapidly.  About 1.2 billion years ago, NGC 4038 and 4039 were two separate galaxies.  Now they are merging.  The interactions caused two giant tails of stars, dust and gas to be pulled away, resulting in the appearance of the antennas on an insect.  The collision has caused a large burst of star formation.  The Antennae are the nearest and youngest examples of merging galaxies.  In the future, the massive black holes in the cores will merge and an elliptical galaxy will form.  This collision could be similar to what will happen to the Milky Way and Andromeda in about five billion years.

Imaging details:

Celestron 9.25" Edge HD SCT with off-axis guider (FL = 2350mm, f/10)
Celestron CGEM II mount
ZWO ASI 1600MM Pro cooled monochrome camera (-15C)
ZWO 36mm Luminance, Red, Green and Blue filters

Software:    Sequence Generator Pro, PHD2 guiding, Celestron CPWI mount control, 
    PixInsight and Photoshop CC 2021/2023

Luminance    2 min x 72 subframes (144 min), Gain 139, Offset 21, 1x1 binning
Red     4 min x 16 subframes (64 min), Gain 139, Offset 21, 1x1 binning
Green    4 min x 18 subframes (72 min), Gain 139, Offset 21, 1x1 binning
Blue    4 min x 22 subframes (88 min), Gain 139, Offset 21, 1x1 binning