(18303) 1980 PU è Binario

Grande soddisfazine nell'aver contribuito alla scoperta di questo nuovo asteroide binario. dall'osservtorio di San Marcello, comìne Martina Maestripeiri, sono state ottenute due sessioni sservative. Era richiesta una precisione di 0.02 mag ed almeno 4 ore conseguitve di osservazione.

e cosi il 10 ottobre esce la
CBET 4676: (18303)1980 PU Binary
 V. Benishek, Belgrade Astronomical Observatory; P. Pravec and P.
Kusnirak, Ondrejov Observatory; R. Durkee, Shed of Science South
Observatory,
Pontotoc, TX, U.S.A.; D. Pray, Sugarloaf Mountain Observatory, South
Deerfield, MA, U.S.A.; V. Chiorny and O. Mikhalchenko, Kharkiv Observatory;
M. Husarik and M. Pikler, Skalnate Pleso Observatory; J. Oey, Blue Mountains
Observatory, Leura, NSW, Australia; P. Bacci and M. Maestripieri,
Astronomical Observatory, San Marcello Pistoiese, Italy; and A. Aznar, Isaac
Aznar Observatory, Alcublas, Valencia, Spain, report that photometric
observations taken with a 0.35-m telescope at the Sopot Observatory in
Serbia, a 0.50-m telescope at the Shed of Science South Observatory, a
0.50-m telescope at the Sugarloaf Mountain Observatory, a 0.70-m telescope
at the Chuguev station of the Kharkiv Observatory in Ukraine, a 0.61-m
telescope at the Skalnate Pleso Observatory, a 0.35-m telescope at the Blue
Mountains Observatory, a 0.60-m telescope at the San Marcello Pistoiese
Observatory, and a 0.35-m telescope at the Isaac Aznar Observatory during
Aug. 10-Oct. 2 reveal that minor planet (18303) is a binary system with an
orbital period of 12.270 +/- 0.003 hr.  The primary shows a period of
2.72627 +/- 0.00010 hr and has a lightcurve amplitude of 0.10 magnitude at
solar phases 4-14 degrees, suggesting a nearly spheroidal shape.  Mutual
eclipse/occultation events that are 0.05 to 0.12 magnitude deep indicate
a secondary-to-primary mean-diameter ratio of 0.24 +/- 0.03.