Electronic Telegram No. 5408
Central Bureau for Astronomical Telegrams
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Prepared using the Tamkin Foundation Computer Network


2020 BD_12
     P. Pravec, P. Kusnirak, K. Hornoch, P. Fatka, and H. Kucakova, Ondrejov
Observatory, report that photometric observations taken with a 1.54-m
telescope at the La Silla station of the European Southern Observatory during
2024 Mar. 13-Apr. 4 reveal that the Amor-type minor planet 2020 BD_12 is a
binary system with an orbital period of 24.25 +/0 0.05 hr.  Mutual eclipse/
occultation events that are 0.33 to 0.55 magnitude deep indicate a lower limit
on the secondary-to-primary mean-diameter ratio of 0.60.  There is apparent a
rotational lightcurve at orbital phases outside the mutual events with a
period equal to the orbital period and an amplitude of 0.22 magnitude at solar
phases 8-23 degrees, suggesting that one or both components of the binary
system are synchronous and moderately elongated.  The system's mean absolute
magnitude is H = 20.78 +/- 0.07 with a phase-relation slope parameter G =
0.15 +/- 0.05.  The color index in the Johnson-Cousins photometric system is
(V - R) = +0.39 +/- 0.03.


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                         (C) Copyright 2024 CBAT
2024 July 9                      (CBET 5408)              Daniel W. E. Green