Source: scribd.com
This list covers UFO sightings by astronomers from 1623 to 2000.
Not one astronomer has ever seen a Space object he couldn’t explain, according to some UFO debunkers.
Many of the astronomers who sighted an unknown object (or objects) were government employees:
http://www.scribd.com/doc/16805639/A-List-of-UFO-Sightings-by-Astronomers
U.S. astronomer Clyde W. Tombaugh sighted between six to eight UFOs over Las Cruces, New Mexico on 20 August 1949, at 10:45 p.m.
Clyde William Tombaugh,U.S. Astronomer