ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 2021/10/02
  STAR: UCAC4 542-011372
  ASTEROID: (771) Libera

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  - 02:31:28    -      -      :
    D  - 02:33:23.84 -      - 0.05 :
    R  - 02:33:24.94 -      - 0.05 :
    E  - 02:35:37    -      -      :

                          Duration : 1.10 +/- 0.07 s
                         Mid-event : 02:33:24.38 +/- 0.04 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: 100 ms

7 OBSERVING CONDITIONS:
  Atmospheric transparency: fair  Wind: no   Temperature: 7 deg C
  Star image stability: fair      Minor planet visible: very barely

8 ADDITIONAL COMMENTS:
  Analyzed using Tangra v3.7.3 and AOTA v4.12.13
  S/N of occulted star: 5.4 - 5.5 (AOTA)
  Camera temperature: -5 deg C
  
  Measured magnitude drop: 1.6 m
  
  Asteroid was not visible during occultation but Tangra light curve contains small
  values above zero.

  The applied approximate recording delay (12 ms) was 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 .

 UKOCL feed (2021/08/26):
  Event time: 02:33:26 UT
  Error in time: 4 s
  Max duration: 2.6 s
  Star magnitude: 12.3 m
  Asteroid magnitude: 13.9 m
  Combined magnitude: 12.1 m
  Magnitude drop: 1.6 - 2.1 m
  Position: In the shadow, 8 km from the central line
  Probability: 51.8 %