Astrometric observations near the maximun approach of the Potencially Hazardous Asteroid (66391) 1999 KW4

Abstract

Our team decided to collaborate with the campaign to observe the maximum approach of the PHA (66391) 1999 KW4, organized by the International Asteroid Warning Network (IAWN). The observations were made from CIEASEST, in the Universidad Nacional San Luis Gonzaga de Ica, Peru (Long. 75 44 12.5 W, Lat. 14 05 21.1 S, Alt. 401 m). A 60 cm Nishimura telescope (f10) and a ZWO ASI 071MC camera were used. The night of the maximum approach (May 25, 2019) we had cloudy skies; however, the night of May 26-27 we had clear skies and we were able to take 147 images with a exposure time of 4 seconds. Dimension 4 software was used to synchronize our time with special purpose Internet Time Servers, ensuring less than one second accuracy. The astrometric measurements were made with the Astrometrica software, using between 15 and 25 stars in the field identified by means of the Gaia DR2 catalog.