ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 02 March 2021             STAR: TYC 1224-00140-1  (11.4 mag)
  ASTEROID: Venusia                  No: 499 

2 OBSERVER: Name: Marek Zawilski            Abbr:

            Address: 91-473 Lodz, Poland

3 OBSERVING STATION: Nearest cities: Lodz and Poddebice
  Station: Tobolice
  Latitude:  51d 54' 46.4" N
  Longitude: 19d 03' 21.9" 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  - 20:22:58    - N/A  - 1    
    D  - 20:23:40.75          0.16               AOTA analysis
    R  - 20:23:44.29          0.11               AOTA analysis
    E  - 20:24:25    - N/A  - 1    
 
                          Duration : 3.54 sec
                         Mid-event : 20:23:42.5
               Predicted mid-event : 02 Mar; 20:23:44 UT  +/- 2 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: GPS Shelyak TimeBox for adjusting the Lenovo laptop clock; A time correction established in relation do the 1pps TimeBox diode pulses: minus 0.05s (-50 ms).
  Sensor: ZWO ASI 120MM, shutter set for 221ms, image resolution 640x480 px, gain 50.
  Recording: SHARPCAP v.3.2.6480.0 software.

7 OBSERVING CONDITIONS:
  Atmospheric transparency: good   Wind: none            Temperature: +5 deg C
  Star image stability: good       Minor planet visible: yes (after the occultation of the target star)

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. 
  The D and R times according to the AOTA analysis. The recorded duration longer than epredicted. 
  Magnitude drop smaller than predicted by the last update from Feb.28 (limit magnitude capability - about 13.5 mag.). 
  Assymetric   lightcurve (rapid D, gradual R), mean S/N 8.3.

  Predicted max. 2.7 sec. duration with 4.2 mag. drop (according to the last update from Feb.28).
  Event probability at site : 61.7%
  Distance from center line : 8 km in 271° direction, inside the predicted path.
  Local * conditions (Alt,Az): 20°, @275°
  Moon (Alt, Az): below the horizon