ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 06 August 2020                   STAR: UCAC4 405-090153  (11.9 mag)
  ASTEROID: de Villegas               No: 15785

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: NEGAITIVE |
                         |                                  |
                         +----------------------------------+
  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  - 22:36:45    - N/A  - 1    :
    D  -   -                       :  
    R  -   -                       :   
    E  - 22:37:30    - N/A  - 1    :
  
                          Duration : no occultation for sure
                         Mid-event : 
               Predicted mid-event : 6 Aug; 22:37:16 UT  +/- 6 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 - offset < +0.05s, delay <0.04s at 21:42-22:44 UT); 
  Sensor: ZWO ASI 120MM, shutter set for 200 ms, image resolution 640x480 px, gain 70 (star faint).
  Recording: SHARPCAP v.3.1.5220.0 software

7 OBSERVING CONDITIONS:
  Atmospheric transparency: good   Wind: none            Temperature: +18 deg C
  Star image stability: average       Minor planet visible: no

8 ADDITIONAL COMMENTS:
 
  The light curve analyze using Tangra software and a careful inspection of the screen replay showed no remarkable drop of the star brightness caused by the asteroid.  
  The star image was stable enough both for the occulted and a guiding star and there was no occultation longer than 0.2s.

  Predicted max 1.3 sec duration with 6.4 mag drop.
  Event probability at site : 8.8%
  Distance from center line : 23.6 km in 236° direction, outside the predicted path, inside the 1-sigma limit
  Local * conditions (Alt,Az): 24°, @8213°
  Moon (Alt, Az): 20°, @8134° at a distance of 72°, not disturbing much.