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Contains:  IC 1110
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UGC 9749 - Ultra-dim Dwarf Galaxy, 


            Gary Imm
UGC 9749 - Ultra-dim Dwarf Galaxy

UGC 9749 - Ultra-dim Dwarf Galaxy

Technical card

Resolution: 4506x3365

Dates:April 8, 2019

Astrodon Blue 31mm Gen2 I-Series: 100x60" (gain: 139.00) -20C bin 1x1
Astrodon Green 31mm Gen2 I-Series: 100x60" (gain: 139.00) -20C bin 1x1
Astrodon Red 31mm Gen2 I-Series: 100x60" (gain: 139.00) -20C bin 1x1

Integration: 5.0 hours

Avg. Moon age: 3.00 days

Avg. Moon phase: 9.85% job: 2685379

RA center: 227.158 degrees

DEC center: 67.219 degrees

Pixel scale: 0.782 arcsec/pixel

Orientation: 357.349 degrees

Field radius: 0.611 degrees

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

Data source: Backyard


This object, one of the dimmest objects I have ever imaged, is the Ursa Minor Dwarf Galaxy. It is a satellite of our Milky Way galaxy, located only 200,000 light years away. It spans 2000 light years and has the same apparent size in the sky as our full moon.

One other image of this object appears on Astrobin. As far as I know, this is the only object on Astrobin where viewing the full resolution image is really necessary to see the object.

Dwarf galaxies are typically low in brightness. This galaxy is a dwarf spheroidal galaxy, which is even more diffuse and poorly defined than a typical dwarf. It is the faintest known galaxy of our local group, with a surface brightness of 25.5.

The galaxy shows up as dim individual points of blue light scattered throughout the center of the image. The galaxy is nearly impossible to see without using the full resolution view. Once you know what you are looking for, it is possible to see the galaxy in the windowed view as a slightly brighter patch of sky that is roughly oval shaped and spans about 1/2 of the image width from upper left to lower right.



Gary Imm
License: None (All rights reserved)

Sky plot

Sky plot


UGC 9749 - Ultra-dim Dwarf Galaxy, 


            Gary Imm