NGC6633 - The Captain Hook Cluster or Tweedledum Cluster

Credits: Keith Turnecliff, Long Itchington

The cluster lies only 1,000 light-years away and many of its stars are bright. Through a 4-inch telescope, more than a dozen of them outshine 10th magnitude. That group appears to sit in front of an additional 50 fainter stars. If you use larger-aperture instruments, keep the magnification around 100x so you don’t disperse the stars so much that you look “through” the cluster.

Facts about NGC6633 by Keith Turnecliff

This cluster is nearly as large as the full moon, and contains 38 stars which make it shine at a total magnitude of 4.6; the brightest star is of mag 7.6. Its age was estimated at 660 million years.

This star chart represents a view from Long Itchington for early July at 10pm.
Credits: Image courtesy of Starry Night Pro Plus 8, researched and implemented by Keith Turnecliff.