This is Messier 46 and Messier 47 in Puppis. M46 is the lower cluster, and within it is contained the planetary nebula NGC 2438. Actually the planetary is not associated with the cluster and is most likely a foreground object.
M46 is about 5,500 light-years away. There are an estimated 500 stars in the cluster, and it is thought to be some 300 million years old.
M47 is at a distance of about 1,600 light-years from Earth with an estimated age of about 78 million years. There are about 50 stars in this cluster, the brightest one being of magnitude +5.7.
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Canon 60D with a Astronomik CLS filter, with a Canon 100-400mm “L” lens, set at 400 mm. 28 subframes of 120 seconds each all at ISO 1600, yielding a total exposure time of 56 minutes. Stacked and processed in Nebulosity.