The Black Moshannon Observatory (BMO) was an astronomical observatory owned and operated by
Penn State University. It was located in the central part of the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

,
at 40°55′18"N 78°00′18"W, with an altitude of 738m above sea level.
The observatory consisted of a 1.6m (62 inch) reflecting telescope. As of the
mid-1990s, the observatory was closed.

The primary instrument attached to the telescope was a fiber-fed, cross-dispersed echelle spectrograph

Echelle grating

An echelle grating is a type of diffraction grating which is characterised by a relatively low groove density but is optimized for high diffraction orders. Echelle gratings are, like other types of diffraction grating, used in spectrometers and similar instruments, such as HARPS, and numerous...

. Astronomers
used this instrument to study chromospherically active stars, binary stars, and pre–main sequence stars, for example.