Photometric observations of the near-Earth asteroid (31345) 1998 PG by Pravec et al. (2000) found a rotation period of 2.51620 h. Also found was a secondary period of 7.0035 h, or the double-period of 14.007 h, possibly indicating an additional body in the system. An extended campaign by the authors in 2018 lead to a similar primary period of 2.5168 h. However, instead of a 7-hour secondary period, one of about 16 hours was found with the lightcurve showing apparent mutual events (occultations and/or eclipses). The data sets from 1998 and 2018 could not be fit to a secondary period near the one found at the opposing apparition. The conclusion is that the asteroid is very likely binary, but - other than the primary rotation period - the system's parameters are ill-defined and only future observations will sufficiently refine them.

APT Observatory Group EURONEAR Valencia SPAIN

Astronomical Institute Academy of Sciences of the Czech Republic Fricova CZ 25165 Ondřejov CZECH REPUBLIC

Belgrade Astronomical Observatory Volgina 7 11060 Belgrade 38 SERBIA

Blue Mountains Observatory Leura NSW AUSTRALIA

Center for Solar System Studies 446 Sycamore Ave Eaton CO 80615 USA

Observatorio de Sierra Nevada Instituto de Astrofisica de Andalucia CSIC SPAIN

Sugarloaf Mountain Observatory South Deerfield MA USA

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