* Astronomy

NGC 6633 (also Melotte 201, Collinder 380 and OCL 90) is a magnitude +4.6 open star cluster located 1040 light-years away in the constellation Ophiuchus.
The cluster was discovered by Swiss astronomer Jean Philippe Loys de Cheseaux using a 2-foot focal length Gregorian reflector at his private observatory at Lausanne, Switzerland, in 1745.
The cluster was independently rediscovered by German astronomer Caroline Herschel using a 10.7 cm (4.2 inch) 24x f/6 Newtonian reflector at Datchet, Berkshire, England, on the 31st July 1783.

Right Ascension 18h 27m 15.1s, Declination +06° 30' 30"

This cluster is nearly as large as the full moon, and contains 30 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.
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