Electronic Telegram No. 5081
Central Bureau for Astronomical Telegrams
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(37424) 2001 YA_3
     V. Benishek, Belgrade Astronomical Observatory; P. Pravec, Ondrejov
Observatory; P. Sogorb, La Bastide des Jourdans, France; and R. Durkee, Shed
of Science South Observatory (SSSO), Pontotoc, TX, U.S.A., report that
photometric observations taken with a 0.35-m telescope at the Sopot
Observatory in Serbia, a 0.28-m telescope at the Bastidan Observatory in
France, and a 0.50-m telescope at the SSSO during Sept. 26-Nov. 7 reveal that
minor planet (37424) is a binary system with an orbital period of 18.956 +/-
0.006 hr.  The primary shows a period of 2.8251 +/- 0.0002 hr and has a
lightcurve amplitude of 0.11 magnitude at solar phases 6-9 degrees, suggesting
a nearly spheroidal shape.  Mutual eclipse/occultation events that are 0.05
magnitude deep indicate a lower limit on the secondary-to-primary mean-
diameter ratio of 0.22.  SSSO observations taken on Nov. 7 showed a 0.07-mag-
deep brightness attenuation centered at Nov. 7.3069 UT and lasting for 35 min
that was not phased to the 0.05-mag-deep mutual events repeating with the
18.956-hr period above; the suspicion that it was a mutual event by a second
satellite needs to be confirmed with future observations.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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2021 December 9                  (CBET 5081)              Daniel W. E. Green