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Contains:  NGC 5395, NGC 5394
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Arp 84 - Heron Galaxy

Technical card

Resolution: 2595x1931

Dates:March 25, 2019March 26, 2019

Astrodon Blue 31mm Gen2 I-Series: 90x30" (gain: 139.00) -20C bin 1x1
Astrodon Green 31mm Gen2 I-Series: 90x30" (gain: 139.00) -20C bin 1x1
Astrodon Lum 31mm Gen2 I-Series: 300x30" (gain: 139.00) -20C bin 1x1
Astrodon Red 31mm Gen2 I-Series: 90x30" (gain: 139.00) -20C bin 1x1

Integration: 4.8 hours

Avg. Moon age: 20.06 days

Avg. Moon phase: 71.36% job: 2635155

RA center: 209.654 degrees

DEC center: 37.439 degrees

Pixel scale: 0.782 arcsec/pixel

Orientation: 0.031 degrees

Field radius: 0.351 degrees

Locations: Backyard (Mag 20.8), Onalaska, Texas, United States

Data source: Backyard


This likeness of a blue heron, with its beak reaching out to spear a nearby fish, is comprised of 3 galaxies - two galaxies which are gravitationally merging, plus a background galaxy. The merging galaxies, known as Arp 84, are located 165 million light-years from Earth in the constellation of Canes Venatici (The Hunting Dogs) at a declination of +37 degrees. I see many herons during the daytime at my house and I can attest that this nickname is visually appropriate.

The structure of each of these galaxies is incredible. The larger galaxy (NGC 5395) is an elongated, face-on spiral galaxy which is asymmetric and distorted due to interaction with its nearby companion. The dominant spiral arm of this galaxy forms two complete rings around the core. A large vertical dark dust lane is bisecting the right side of the galaxy.

The smaller galaxy (NGC 5394) is also a face-on galaxy. It has an oval disk, two long symmetric arms, and very bright inner spiral arms.

It is interesting that both of these galaxies appear to be face-on. The cores of these two galaxies are separated by 2 arc-minutes (about 100,000 light years, the diameter of our Milky Way). For both galaxies, I like the color contrast between the outer reaches of the galaxy arms (blue) and the core / inner regions (yellow).

Also seen in this image are many background galaxies, including the "fish" (PGC 2101092).



Gary Imm
License: None (All rights reserved)

Sky plot

Sky plot


Arp 84 - Heron Galaxy, 


            Gary Imm