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Contains:  M 3, M3, NGC 5272, NGC5263
Getting plate-solving status, please wait...
M3 magnificent globular, 


            Barry Wilson
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M3 magnificent globular

Technical card

Dates:May 15, 2017

Astrodon E-Series Blue filter: 8x300" bin 1x1
Astrodon E-Series Green filter: 8x300" bin 1x1
Astrodon E-Series Red filter: 8x300" bin 1x1
Astrodon Luminance E-Series: 15x300" bin 1x1

Integration: 3.2 hours

Avg. Moon age: 18.88 days

Avg. Moon phase: 82.00% job: 1585921

RA center: 13h 42' 4"

DEC center: +28° 22' 51"

Pixel scale: 2.872 arcsec/pixel

Orientation: -88.753 degrees

Field radius: 1.605 degrees

Resolution: 3227x2405

Locations: Home observatory, Totnes, Devon, United Kingdom

Data source: Backyard


When I was gathering the last few RGB subs for my MW3, Volcano Nebula, M81/82 mosaic, I was only able to track the four panels for about 1.5 hours before they disappeared behind a tree. The moon was making its presence felt at that point but I made use of the clear skies by switching to target the globular cluster M3 for the balance of the astro dark. So a smash and grab M3 after my mosaic madness was a cathartic counterpoint and a sign-off before Nebula season.

The data only amounts to 15 x 300s luminance and 8 x 300s each RG&B, a total of 3hrs 25mins, but just about do-able for a wide-ish look at M3. The FSQ106 at F3.6 and QSI683 giving 2.8"/px isn't the tool for resolution to the core but it is a fun image nevertheless. I have decided against cropping to show the concentrated globular aggregation of stars in context against the starfield.

According to Wikipedia, "Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13.[1] . . . This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 8 billion years old. It is located at a distance of about 33,900 light-years away from Earth.[citation needed]. . . It contains 274 known variable stars; by far the highest number found in any globular cluster."

Having recently read "The Glass Universe" by Dava Sobel which documents the extraordinary work of the female 'human computers' at Harvard University cataloguing stars, their positions, their spectra and their significant contributions to astronomy and especially variable stars and their brightness/periodicty relationship, it is rather pleasing to capture M3 with its abundant stars and variables.



Barry Wilson
License: None (All rights reserved)

Sky plot

Sky plot


M3 magnificent globular, 


            Barry Wilson

In these public groups

UK Astro-Imaging