ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 2022/09/02
  STAR: UCAC4 578-017626
  ASTEROID: (772) Tanete

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  - 02:10:05    -      -      :
    B  - 02:12:15.12 -      - 0.35 : 0.3 mag drop on single frame, possible noise
    D  - 02:14:17.27 -      - 0.35 :
    R  - 02:14:21.47 -      - 0.35 :
    E  - 02:18:49    -      -      :

                          Duration : 4.20 +/- 0.50 s
                         Mid-event : 02:14:19.37 +/- 0.25 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: 700 ms

7 OBSERVING CONDITIONS:
  Atmospheric transparency: fair  Wind: no   Temperature: 11 deg C
  Star image stability: fair      Minor planet visible: yes

8 ADDITIONAL COMMENTS:
  Analyzed using Tangra v3.7.4 and AOTA v4.2022.8.18
  S/N of occulted star: 5.7 - 5.5 (AOTA)
  Camera temperature: -20 deg C

  Expected magnitude drop: 0.3 mag (measured 14 minutes before
  the occultation in ASTAP)

  Observed magnitude drop: 0.3 mag (AOTA)

  Applied approximate recording delay: 17 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)

  Gaia RUWE: 1.55 (beware)

 IBEROC feed (2022/07/15):
  Event time: 02:14:19 UT
  Error in time: 2 s
  Max duration: 5.5 s
  Star magnitude: 15.2 mag
  Asteroid magnitude: 14.5 mag
  Combined magnitude: 14.0 mag
  Magnitude drop: 0.5 mag
  Position: In the shadow, 62 km from the central line
  Probability: 97.7 %

Observed smaller light drop than predicted but it was consistent with relative brightness of the asteroid and the occulted star measured shortly before the occultation. Potentially this could be explained by different characteristic of ASI 174MM camera vs. Gaia sensors.