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Contains:  NGC 5474, NGC5474, PGC2448110
Getting plate-solving status, please wait...
NGC 5474 - Companion to M101, 



    
        

            Gary Imm
NGC 5474 - Companion to M101, 



    
        

            Gary Imm

NGC 5474 - Companion to M101

Technical card


Dates:May 15, 2020May 16, 2020

Frames:
Astrodon Blue 31mm Gen2 I-Series: 30x120" (gain: 139.00) -20C bin 1x1
Astrodon Green 31mm Gen2 I-Series: 30x120" (gain: 139.00) -20C bin 1x1
Astrodon Lum 31mm Gen2 I-Series: 60x120" (gain: 139.00) -20C bin 1x1
Astrodon Red 31mm Gen2 I-Series: 30x120" (gain: 139.00) -20C bin 1x1

Integration: 5.0 hours

Avg. Moon age: 23.43 days

Avg. Moon phase: 36.59%


Astrometry.net job: 3616193

RA center: 14h 5' 1"

DEC center: +53° 39' 50"

Pixel scale: 0.281 arcsec/pixel

Orientation: -1.065 degrees

Field radius: 0.150 degrees


Resolution: 3150x2209

Data source: Backyard

Description

This object is a spiral dwarf galaxy located only 23 million light years away in the constellation of Ursa Major at a declination of +53 degrees. This 10.8 magnitude galaxy spans 4 arc-minutes in our apparent view, which corresponds to an actual diameter of 30,000 light years.

This galaxy is one of the numerous companions of M101 (Pinwheel Galaxy). M101 is located about 1 degree north, above the frame of this image.

The gravitational interaction with M101 has in resulted an offset core. Adam Block has an interesting discussion of this core effect here, along with a beautiful image. He says that, as NGC 5474 orbits M101, a core asymmetry occasionally develops that is described as a “sloshed agitation”, depending upon the rotational directions of these 2 galaxies relative to each other. So this offset varies over time and is not a permanent “pull” of gravity.

Numerous blue star clusters and pink Ha regions have been initiated by this disturbance. Looking closely, the galaxy appears a bit grainy in my image. Adam attributes this graininess to partial resolution of many of the brighter stars (20 magnitude) in this nearby galaxy.

This dwarf galaxy is the only one I recall imaging that is classified as a spiral galaxy. Some faint spiral structure is seen in the disk.

I included a Hubble image in the mouseover which shows more galaxy detail in the core area.

Comments

Author

GaryI
Gary Imm
License: Attribution-NonCommercial Creative Commons
1834
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Revisions

  • Final
    NGC 5474 - Companion to M101, 



    
        

            Gary Imm
    Original
  • NGC 5474 - Companion to M101, 



    
        

            Gary Imm
    C

C

Description: Hubble Image Mouseover

Sky plot

Sky plot

Histogram

NGC 5474 - Companion to M101, 



    
        

            Gary Imm