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Contains:  M 2, NGC 7089
Getting plate-solving status, please wait...


            Steve Lantz


Technical card

Resolution: 1580x1200

Dates:Oct. 4, 2019

Frames: 134x19"

Integration: 0.7 hours

Avg. Moon age: 6.22 days

Avg. Moon phase: 37.79% job: 2972559

RA center: 323.360 degrees

DEC center: -0.853 degrees

Pixel scale: 1.336 arcsec/pixel

Orientation: 275.716 degrees

Field radius: 0.368 degrees

Locations: Backyard, Aurora, CO, United States

Data source: Backyard


M2 is a relatively large globular cluster located in Aquarius. It lies at a distance of 55,000 LY from earth and has a diameter of 175 LY, which translates to about 1 star per 19 cubic LY on average. It is interesting to imagine what the night skies would look like from a planet orbiting a star in a globular cluster. We can get an idea from a simulation done by astronomers William Harris and Jeremy Webb (, who used 47 Tucanae as their globular cluster (diameter = 120 LY and population = 570,000 stars). The highlights are that an observer on a planet orbiting a star at the center of 47 Tucanae would see the nearest star at a distance of about 0.05 LY, about 10,000 stars brighter than 1st magnitude scattered across the sky, and a night-time brightness of about twenty times greater than a night on earth with a full moon. The very stars themselves would be a source of light pollution! The posted image is a composite of 50 subs at 25s each and 84 subs at 15s each. These are the subs that remained after many others were culled due to periodic drive error (the images were all unguided) and wind shudder. The 15s images were primarily used to provide a masked view of the center of the cluster's image. As usual, seeing was poor in the Denver area.



Steve Lantz
License: None (All rights reserved)

Sky plot

Sky plot




            Steve Lantz