Browsing by Author "Zegarra-Valles, M."
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Item Open Access Astrometric observations near the maximun approach of the Potencially Hazardous Asteroid (66391) 1999 KW4(The Astronomer's Telegram, 2019-08-08) Ricra, J.; Zegarra-Valles, M.; Baella, Nobar; Villanueva, R.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.Item Open Access Astrometric observations of the Potentially Hazardous Asteroid (52768) 1998 OR2 near its maximum approach to earth(The Astronomer's Telegram, 2020-05-13) Villanueva, R.; Ricra, J.; Zegarra-Valles, M.; Baella, Nobar; Santivanez, J.Our team presents astrometric measurements of the PHA (52768) 1998 OR2 obtained close to its maximum approach to Earth. The observations were made from Observatorio Planetario Moche, located in Trujillo, Peru (Long. 79 00 39.2 W, Lat. 08 06 47.9 S, Alt. 48 m), on April 23, 24, 25 and 29, 2020. It is important to note that April 29's measurements were obtained approximately 5 hours before the asteroid's closest approach to Earth. A Celestron NexStar 11 GPS telescope and a ZWO ASI 071MC camera (without filter) were used. In addition, Dimension 4 software was employed to synchronize our time with special purpose Internet Time Servers. A total of 240 images were obtained, of which 19 were selected for presenting better ellipticity and FWHM values. The astrometric measurements were made with the Astrometrica software, using between 13 and 31 field stars identified by means of the Gaia DR1 catalog.