Alvan Clark Jr.

Alvan Graham Clark Jr. (1832-1897) was an American astronomer and telescope maker of significant importance to observational astronomy, though not directly involved in UAP/UFO research or military programs. He is best known for discovering Sirius B, the companion star to Sirius, on January 31, 1862, using a telescope—a discovery that preceded theoretical predictions of the star's existence. Clark's astronomical work and precision instruments contributed to the broader field of sky observation and celestial documentation that forms the historical foundation for modern astronomical research.