December 2023: please visit the updated version of this target
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I acquired two series of subexposures on the 2nd and 3rd March 2023, with exposures respectively of 180" and 120". After integrating the two series, I kept the 120" exposures only.
The Double ClusterThe Double Cluster (also known as Caldwell 14) consists of the open clusters NGC 869 and NGC 884, which are really close together, not only optically. Both visible with the naked eye, NGC 869 and NGC 884 lie at a distance of about 7,500 light years in the Perseus Arm of the Milky Way galaxy.
NGC 869 has a mass of 4700 solar masses and NGC 884 weighs in at 3700 solar masses; both clusters are surrounded with a very extensive halo of stars, with a total mass for the complex of at least 20,000 solar masses. They form the core of the Perseus OB1 association.
Based on their individual stars, the clusters are relatively young, both 14 million years old. In comparison, the Pleiades have an estimated age ranging from 75 million years to 150 million years.
There are more than 300 blue-white super-giant stars in each of the clusters. The clusters are also blue-shifted, with NGC 869 approaching Earth at a speed of 39 km/s and NGC 884 approaching at a similar speed of 38 km/s.
(notes excerpted by Wikipedia)
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