5905 Johnson

5905 Johnson, provisional designation 1989 CJ1, is a Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 11 February 1989, by American astronomer Eleanor Helin at Palomar Observatory in California, United States. Its satellite measures approximately 1.6 km (1 mi) in diameter and orbits its primary every 21.8 hours. It was named after American astronomer and engineer Lindley N. Johnson.