ASTEROIDAL OCCULTATION - REPORT FORM +------------------------------+ +------------------------------+ | EAON | | IOTA/ES | | | | INTERNATIONAL OCCULTATION | | EUROPEAN ASTEROIDAL | | TIMING ASSOCIATION | | OCCULTATION NETWORK | | EUROPEAN SECTION | +------------------------------+ +------------------------------+ 1 DATE: 2022/07/20 STAR: UCAC4 492-147628 ASTEROID: (972) Cohnia 2 OBSERVER: Name: Daniel BLAZEWICZ Address: 32-015 Klaj, POLAND 3 OBSERVING STATION: Klaj Nearest city: Niepolomice (Poland) Longitude: E 20 19 04.2 (WGS84) Latitude: N 49 59 33.2 (WGS84) Altitude: 211 m (MSL) Single station +----------------------------+ 4 TIMING OF EVENTS: | | | EVENT REPORTED: POSITIVE | | | +----------------------------+ Event code S: observation Start I: Interruption start D: Disappearance J: Interruption end R: Reappearance B: Blink F: Flash E: observation End O: Other (specify) Abbreviations P.E.: Personal Equation = reaction time (for visual obs) Acc.: Accuracy (overall accuracy of the given time) Comments Event Time (UT) P.E. Acc. Code HH:MM:SS.ss S.ss S.ss S - 01:51:30 - - : D - 01:53:28.73 - - 0.08 : R - 01:53:39.48 - - 0.07 : E - 01:56:34 - - : Duration : 10.75 +/- 0.10 s Mid-event : 01:53:34.10 +/- 0.05 s 5 TELESCOPE: Type: NEWTON Aperture: 350 mm Magnification: prime focus f/4.8 Mount: EQUATORIAL with polar wedge Motor drive: YES 6 TIMING & RECORDING: Time source: "chrony", 4 x NTP Stratum 1, Linux Ubuntu, 1 sigma < 1 ms Sensor: ZWO ASI174MM-C Recording: ZWO ASICAP V2.3 Exposure: 100 ms 7 OBSERVING CONDITIONS: Atmospheric transparency: good Wind: weak Temperature: 14 deg C Star image stability: good Minor planet visible: yes 8 ADDITIONAL COMMENTS: Analyzed using Tangra v3.7.4 and AOTA v4.2022.7.5 S/N of occulted star: 3.4 - 3.5 (AOTA) Camera temperature: -10 deg C Measured light drop: 1.1 mag (AOTA) Sun altitude: -8 deg Applied approximate recording delay: 12 ms (based on the report for similar hardware configuration and the same both USB setting and ROI, and similar exposure, published by Pierre Le Cam on http://www.nocturno.fr/ost/ost.html) ITALOccult feed (2022/07/02): Event time: 01:53:34 UT Error in time: 5 s Max duration: 9.8 s Star magnitude: 13.1 m Asteroid magnitude: 13.9 m Combined magnitude: 12.7 m Magnitude drop: 1.2 m Position: In the shadow, 4 km from the central line Probability: 88.9 %