ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 2022/07/18
  STAR: UCAC4 345-191775
  ASTEROID: (7994) Bethellen

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  - 20:03:00    -      -      :
    D  - 20:06:18.71 -      - 0.18 :
    R  - 20:06:20.10 -      - 0.18 :
    E  - 20:09:22    -      -      :

                          Duration : 1.39 +/- 0.25 s
                         Mid-event : 20:06:19.41 +/- 0.12 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: 350 ms

7 OBSERVING CONDITIONS:
  Atmospheric transparency: poor  Wind: weak   Temperature: 16 deg C
  Star image stability: fair      Minor planet visible: no

8 ADDITIONAL COMMENTS:
  Analyzed using PyMovie v3.4.2 and AOTA v4.2022.7.5
  S/N of occulted star: 4.1 - 6 (AOTA)
  Camera temperature: -20 deg C
  
  Star disappears on recording however PyMovie detects light drop: 1.8 mag

  Applied approximate recording delay: 26 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)

 CentralEurope feed (2022/05/20):
  Event time: 20:06:17 UT
  Error in time: 2 s
  Max duration: 1.3 s
  Star magnitude: 13.2 m
  Asteroid magnitude: 17.3 m
  Combined magnitude: 13.2 m
  Magnitude drop: 4.1 m
  Position: In the shadow, 25 km from the central line
  Probability: 53.7 %