Electronic Telegram No. 5563
Central Bureau for Astronomical Telegrams
Mailing address:  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


(48489) 1992 EZ_28
     D. Augustin (using a 0.35-m telescope at the e-EyE Observatory, Fregenal
de la Sierra, Spain); R. Behrend, Geneva Observatory; M. Conjat, Observatoire
de la Cote d'Azur (using a 0.40-m telescope at the Nice Observatory); E.
Barbotin (using a 0.50-m telescope at La Grande Vallee Observatory, Etriac,
France); J.-F. Gout (using a 0.28-m telescope at Tree Gate Farm Observatory,
Starkville, MS, USA); A. Wuensche (using a 0.35-m telescope at the DeepSky
Chile Observatory, Rio Hurtado, Chile); and R. Nicollerat (using a 0.35-m
telescope at Observatoire des Valentines, Bex, Switzerland) report that
photometric observations taken during eight nights from 2025 Mar. 25 to Apr.
8 reveal that minor planet (48489) is a binary system with an orbital period
of 22.81 +/- 0.01 hr.  The primary shows a period of 3.0670 +/- 0.0005 hr with
a lightcurve amplitude of 0.06 magnitude at solar phases 4-6 degrees.  Mutual
eclipse/occultation events that are 0.11 to 0.15 magnitude deep indicate a
lower limit on the secondary-to-primary mean-diameter ratio of 0.33.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2025 CBAT
2025 June 6                      (CBET 5563)              Daniel W. E. Green