Electronic Telegram No. 4374
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)
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Prepared using the Tamkin Foundation Computer Network


(1798) WATTS
     D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, H. Kucakova, J. Vrastil, K. Hornoch, and P. Kusnirak, Ondrejov
Observatory; W. Cooney and J. Gross, Sonoita Research Observatory, Sonoita,
AZ, U.S.A.; D. Terrell, Southwest Research Institute; B. Flanagan and B.
Pellerin, Madrona Peak Observatory, Medina, TX, U.S.A.; and J. Oey, Blue
Mountains Observatory, Leura, NSW, Australia, report that photometric
observations taken with a 0.50-m telescope at the Sugarloaf Mountain
Observatory, a 0.65-m telescope at the Ondrejov Observatory, a 0.50-m
telescope at the Sonoita Research Observatory, a 0.6-m telescope at the
Madrona Peak Observatory, and a 0.35-m telescope at the Blue Mountains
Observatory during 2017 Jan. 31-Mar. 15 reveal that minor planet (1798) is
a binary system with an orbital period of 26.96 +/- 0.01 hr.  The primary
shows a period of 3.5060 +/- 0.0004 hr and has a lightcurve amplitude of
0.06 mag at solar phase 5 degrees, suggesting a nearly spheroidal shape.
Mutual eclipse/occultation events that are 0.06- to 0.11-magnitude deep
indicate a secondary-to-primary mean-diameter ratio of 0.25 +/- 0.02.
The mean absolute R magnitude in the Cousins system is H_R = 12.81 +/- 0.08,
assuming the phase relation slope parameter G = 0.24 +/- 0.11.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2017 CBAT
2017 March 19                    (CBET 4374)              Daniel W. E. Green