Electronic Telegram No. 4097
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


(4541) MIZUNO
      D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, K. Hornoch, P. Kusnirak, J. Vrastil and H. Kucakova, Ondrejov
Observatory; Yu. N. Krugly and V. Shevchenko, Kharkiv Observatory; R.
Inasaridze and V. Ayvazian, Abastumani Observatory; J. Oey, Blue Mountains
Observatory, Leura, NSW; W. Cooney and J. Gross, Sonoita Research Observatory,
Sonoita, AZ, USA; D. Terrell, Southwest Research Institute; and I. Molotov,
Keldysh Institute of Applied Mathematics, Moscow; report that photometric
observations obtained during Feb. 24-Apr. 25 reveal that minor planet (4541)
is a binary system with an orbital period of 29.68 +/- 0.01 hr.  The primary
shows a period of 2.82784 +/- 0.00005 hr, and it has a lightcurve amplitude of
0.08 mag at solar phases 3-15 deg, suggesting a nearly spheroidal shape.
Mutual eclipse/occultation events that are 0.06- to 0.15-magnitude deep
indicate a lower limit on the secondary-to-primary mean-diameter ratio of
0.24.  The mean absolute R magnitude of the system is H_R = 12.50 +/- 0.04
and the slope parameter G = 0.11 +/- 0.04.
      V. Reddy and D. Takir, Planetary Science Institute, Tucson, report that
near-infrared spectroscopic observations (0.7-2.5 microns) of minor planet
(4541), obtained on Apr. 26 using the NASA Infrared Telescope Facility on
Mauna Kea, show that it is an S-type minor planet with surface composition
dominated by the minerals olivine and pyroxene.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 May 10                      (CBET 4097)              Daniel W. E. Green