Explanation:
Most star clusters are singularly impressive.
Open clusters NGC 869 and NGC 884,
however, are doubly impressive.
Also known as "h and chi Persei", this unusual
double cluster, shown above, is bright enough to be seen from a
dark location without even
binoculars.
Although their discovery surely predates
written history, the Greek astronomer
Hipparchus notably cataloged the "double
cluster".
The clusters are over 7,000 light years distant toward the
constellation of
Perseus, but are separated by only hundreds of light years.