NGC 6633 is an open star cluster located in the constellation Ophiuchus. It was discovered by the astronomer William Herschel in 1784. The cluster is approximately 2,000 light-years away from Earth and contains around 50 stars, which are relatively young, with ages estimated between 100 and 200 million years. The stars in NGC 6633 are loosely bound by gravity and are spread over a region about 20 light-years in diameter. This cluster is notable for its bright stars, which can be observed with binoculars under dark skies. It is a popular target for amateur astronomers and astrophotographers.