ASTEROIDAL OCCULTATION - REPORT FORM

    +------------------------------+  +------------------------------+
    |            EAON              |  |            IOTA/ES           |
    |                              |  |   INTERNATIONAL OCCULTATION  |
    |     EUROPEAN  ASTEROIDAL     |  |      TIMING  ASSOCIATION     |
    |     OCCULTATION NETWORK      |  |       EUROPEAN SECTION       |
    +------------------------------+  +------------------------------+

1 DATE: 24 October 2019                   STAR: UCAC4 374-148046  (11.9 mag)
  ASTEROID: Kuiper                No: 1776

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  - 18:11:00    - N/A  - 1    :
    D  - 18:13:17.9  -      - 0.3  :   
    R  - 18:13:18.8 -       - 0.3  :   R on two frames? not sure
    E  - 18:15:00    - N/A  - 1    :
  
                          Duration : 0.9 s; (predicted max. 1.6sec)
                         Mid-event : 18:13:18.35
               Predicted mid-event : 24 Oct; 18:13:19 UT  +/- 3 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 "vega.cbk.poznan.pl", laptop-time synchronized better than 0.01s, response of about 10 Polish ntp time servers checked every one minute with the use of the professional software by T.Kluwak, regarding the time offset and response delay (both of very low value and stable - offset less than 0.01s, delay 0.03s at 18:13-18:14 UT);  
However, additional definitive time correction based on DCF77 receiver with a blinking 1PPS diode was applied - an offset of -0.010s to the laptop synchronised time has been considered in final results. The blinking DCF 77 diode has been recorded soon after the observation using the same set of the camera but with a short exposition time of 8 ms.
  Sensor: ZWO ASI 120MM, shutter set for 300 ms, image resolution 1024x968 px, gain 100.
  Recording: ASI Cap v.1.6.1 software.

7 OBSERVING CONDITIONS:
  Atmospheric transparency: very good   Wind: none              Temperature: 11 deg C
  Star image stability: moderate      Minor planet visible: no

8 ADDITIONAL COMMENTS:
 
  The light curve analyze using Tangra software with gamma of 1.5 gave no coherent results so far.
  The dis- and reappearance clearly noticed on screen during the recording analyze - directly using VirtualDub software and watching sequential frames.
  Predicted max 1.6 sec duration with 5.3 mag drop.
  Event probability at site : 22%, but the station in shadow.
  Distance from center line : 17.9 km (on the northern side).
  Local * conditions (Alt,Az): 14°, @220°
  Despite the cloudless sky, quite high humidity of air disturbing optical elements; a warm air blow used periodically before the proper recording action; besides: low altitude; star very faint in such conditions.