ASTEROIDAL OCCULTATION - REPORT FORM +------------------------------+ +------------------------------+ | EAON | | IOTA/ES | | | | INTERNATIONAL OCCULTATION | | EUROPEAN ASTEROIDAL | | TIMING ASSOCIATION | | OCCULTATION NETWORK | | EUROPEAN SECTION | +------------------------------+ +------------------------------+ 1 DATE: 20 May 2017 STAR: UCAC4 38575921 ASTEROID: 2002 GZ32 N?: 95626 2 OBSERVER: Name: Tim HAYMES Abbr: TVH E-mail: tvh.observatory@btinternet.com Address: Hill Rise, Knowl Hill Common, RG10 9YD, UK 3 OBSERVING STATION: Nearest city: READING Station: Fixed Latitude: N 51 30 23".8 Longitude:W 00 48 58".2 Altitude: 75m Datum (WGS84 preferred): WGS84 Single, OR Double or Multiple station (Specify observer's name): Single +----------------------------------+ 4 TIMING OF EVENTS: | | | OCCULTATION RECORDED: NEGATIVE | | | +----------------------------------+ Type of event Start observation Interrupt-start Disappearance Blink Flash End observation Jnterrupt-end Reappearance Other (specify) Comments Event Time (UT) P.E. Acc. Code HH MM SS.ss S.ss S.ss S - 0120:00 - - : 0.32s integration (x16 fields) - - - : D - - - : R - - - : - - - : E - 0142:00 - - : Duration : Mid-event : Predicted 0132-0133 Was your reaction time applied to the above timings? 5 TELESCOPE: Type: NEWTONIAN Aperture: 300mm Magnification: Prime focus F/4 Mount:EQ6 Motor drive: Yes 6 TIMING & RECORDING: Time source: GPSBOXSPRITE2-U Sensor: WATEC 910HX/RC Recording: Sony TRV22E DV camcorder Time insertion (specify): 1 PPS Event insertion (specify): TANGRA analysis 7 OBSERVING CONDITIONS: Atmospheric transparency: GOOD Wind: 0 Temperature: +7 C Star image stability: GOOD Minor planet visible: NO 8 ADDITIONAL COMMENTS: Clearing weather was anticipated after rain. The forecast was correct and the sky was excellent. SQM-L (Zenith) = 20.25 (Mag/arcsec^2). An update to the GPS catalogue was downloaded before observation started and the field arround HIP 82374 was recorded for 22 min centred on 0132 UT (0120-0142UT). The digital tape was converted to AVI in three overlaping time sections: 20-30m, 28-36m and 35-42m. Each recording was run through TANGRA. The reference stars used for the 28-36min recording were: Comparison star:4U 385-075934 Mag 12.9 Guide star :4U 385-075899 Mag 9.8 (SAO 160119, HIP 82374) The target star was indentified from the coordinates using ALADIN. An annotated print-out from SkyMap was used at the telescope and a goto HIP 82374 was commanded. A test sequence at x8 (0.16s) was tried, but decided to err on caution incase of deterioration in conditions so x16 (0.32s)was used. The S/N on the target at x16 was about 7 with no bad drop-outs. NOTE: An unexpected brightening of the guide star HIP 82374 occured at 0133 08.3s, duration 1.4sec. Unusual atmospherics or some other reason?? *** This event was predicted by the Grenada, Paris and Rio team. *** LINK: http://ocultacions.astrosabadell.org/IBEROC/20170520_-75921_summary.html Integration : 0.32 s Gain : 36 dB S/N (Tangra) : 7 Gamma : 1.0 Combined Mag : r 13.5 Predicted drop : 6 Max. Duration : 10.9s OW Distance : 491Km at 189d OW probability : 5.2% Alt/Az : 25 @ 187 Moon : None Field of View : 13 x 18 arc minutes Constellation : Ophiuchus SQM-L (Zenith) : 20.25 Limit of detection : about 14 to 14.5