ASTEROIDAL OCCULTATION - REPORT FORM +------------------------------+ +------------------------------+ | EAON | | IOTA/ES | | | | INTERNATIONAL OCCULTATION | | EUROPEAN ASTEROIDAL | | TIMING ASSOCIATION | | OCCULTATION NETWORK | | EUROPEAN SECTION | +------------------------------+ +------------------------------+ 1 DATE: 09 September 2020 STAR: UCAC4 509-128148 (14.0 mag) ASTEROID: Aidamina No: 978 2 OBSERVER: Name: Marek Zawilski Abbr: Address:91-473 Lodz, Poland 3 OBSERVING STATION: Nearest cities: Lodz and Poddebice Station: Tobolice Latitude: 51d 54' 48.3" N Longitude: 19d 03' 22.4" E Altitude: 140m MSL Datum (WGS84 preferred): WGS84 Single, OR Double or Multiple station (Specify observer's name): SINGLE +----------------------------------+ 4 TIMING OF EVENTS: | | | OCCULTATION RECORDED: POSITIVE | | | +----------------------------------+ 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 - 21:55:03 - N/A - 1 D - 21:56:08.33 0.26 AOTA analysis R - 21:56:16.46 0.26 AOTA analysis E - 21:57:00 - N/A - 1 Duration : 8.13 sec Mid-event : 21:56:12.39 Predicted mid-event : 09 Sep; 21:56:07 UT +/- 7 sec Was your reaction time applied to the above timings? N/A 5 TELESCOPE: Type: Cassegrain Aperture: 203mm Magnification: --- Mount: Equatorial Motor drive: YES Foc.length: 2032mm reduced to 1016mm 6 TIMING & RECORDING: Time source: NTP via Dimension4 using the time server "tempus1.gum.gov.pl", Warsaw, laptop-time synchronized better than 0.01s, response of about 10 Polish ntp time servers checked evry one minute with the use of the professional software by T.Kluwak, regarding the time offset and resopose delay (both of very low value and stable); A time correction established in relation do the 1pps DCF-77 diode pulses: minus 0.04s. Sensor: ZWO ASI 120MM, shutter set for 524 ms, image resolution 640x480 px, gain 80. Recording: SHARPCAP v.3.2.6383.0 software 7 OBSERVING CONDITIONS: Atmospheric transparency: good Wind: none Temperature: +15 deg C Star image stability: good Minor planet visible: no 8 ADDITIONAL COMMENTS: The light curve analyze using Tangra software and a careful inspection of the screen replay showed a remarkable drop of the star brightness caused by the asteroid. The star image was stable enough both for the occulted and a guiding star. This was an occultation of the faintest star I have ever observed. Predicted max. 9.0 sec duration with 0.6 mag drop. Event probability at site : 61.1% Distance from center line : 16.5 km in 120° direction, inside the predicted path. Local * conditions (Alt,Az): 42°, @225° Moon (Alt, Az): 13°, @72° at a distance of 119°, not disturbing the observation.