Precovery of (152563) 1992 BF

In June of 2002, I found and measured two trails of the Aten asteroid (152563) 1992 BF in the DSS database, from Jan. 10 and Jan. 12, 1953. I was hopeful that the data would extend the timespan of observations and improve the orbit, so I was very disappointed when the observations were ultimately rejected; they could not be reconciled with recent astrometry.

In 2006, during the 38th Annual Meeting of the Division for Planetary Sciences, Chesley, Vokrouhlický, and Matson presented their paper Direct Measurement of the Yarkovsky Effect Acting on Near-Earth Asteroid 1992 BF. They showed that the inconsistency of the 1953 images with a purely gravitational solution could be eliminated by incorporating a Yarkovsky effect into the asteroid's motion.

(152563) 1992 BF was the first asteroid to exhibit a measurable Yarkovsky effect primarily through the use of archival photographic data.

See also Steve Chesley's talk from the 2007 Conference of the Society for Astronomical Sciences.

In the following images, the trail of the asteroid is situated at the center of the display, and is nearly vertical.
1953 Jan. 10

10-minute exposure

Size = 240" x 240"

Palomar Mountain-DSS plate XO199 (A3EN)

1953 Jan. 12

10-minute exposure

Size = 240" x 240"

Palomar Mountain-DSS plate XO200 (A3EO)

DSS precovery images are from DSS plate archive scans, which are © copyright California Institute of Technology.