Electronic Telegram No. 3176
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


(5143) HERACLES
     P. A. Taylor, M. C. Nolan, and E. S. Howell, Arecibo Observatory,
National Astronomy and Ionosphere Center, report that Arecibo (2380-MHz,
12.6-cm) radar observations on 2011 Dec. 10-13 reveal that minor planet (5143)
is a binary system.  Visible range extents in 300-m-resolution radar images
suggest component diameters of 3.6 +/- 1.2 km for the primary and 0.6 +/- 0.3
km for the secondary.  Detections of the secondary are consistent with an
orbital period between 14 and 17 hours and imply a separation of at least
4 km.  An orbital period between 40 and 57 hours with an implied separation of
at least 11 km cannot be ruled out, but this is inconsistent with the
assumption of a synchronously rotating secondary.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 July 13                     (CBET 3176)              Daniel W. E. Green