ASTEROIDAL OCCULTATION - REPORT FORM

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

 1 DATE: 21 October 2020                               STAR: UCAC4 473-000544

  ASTEROID: CERGA                                 No: 2252

 2 OBSERVER : 
  Name      : Anna Marciniak                         Abrr: 
  Address   : Astronomical Observatory Institute, A. Mickiewicz University, Sloneczna 36, Poznan, Poland

 3 OBSERVING STATION: 
  Nearest city : Poznan
  Station      : Borowiec          IAU obs code: 187
  Latitude     : 52 16 36.8 N   
  Longitude    : 17 04 30.8 E   
  Altitude     : 123 MSL

  Datum (WGS84 preferred): WGS84

  Single, OR Double or Multiple station (Specify observer's name): single

 4 TIMING OF EVENTS:  
  +----------------------------------------------+
  |       OCCULTATION RECORDED: UNCERTAIN         |
  +----------------------------------------------+
  Type of event:
 "S"tart observation   "I"nterrupt-start   "D"isappearance   "B"link   "F"lash
 "E"nd observation     "J"nterrupt-end     "R"eappearance    "O"ther (specify)

  Event   Time (UT)    P.E.   Acc.   
  Code   HH MM SS.ss   S.ss   S.ss
  
  S  - 22:15:29.0   -    - 1.0
  D  -    -    - 
  B  - 22:21:30.8   -    - 1.0  
  R  -    -    - 
  E  - 22:25:57.0   -    - 1.0 
 
  Predicted max. duration (secs) : 2.2 
  Predicted max. drop (mag)      : 2.6
  Predicted mid-event (UT)       : 22:21:26
  Predicted error in time (secs) : 7

  Was your reaction time applied to the above timings? - not relevant, CCD imaging.
  
 5 TELESCOPE: 
  Type        : Newton  f/4.5                          Aperture   : 400 mm
  Focal length: 1800 mm                                FOV        : 12.0'x 8.0'
  Mount       : paralactic                             Motor drive: yes

 6 TIMING & RECORDING:
  Time source      : ntp server vega.cbk.poznan.pl
  Sensor           : SBIG ST7 CCD camera with KODAK KAF400 sensor
  Mode of recording: Resolution: Low, Vertical binning: 2, Image size: Half
  Shutter (SENS-UP): Mechanical
  Recording        : Personal Computer
  Recording        : CCDOps software
  Time insertion   : none

 7 OBSERVING CONDITIONS: 
  Atmospheric transparency          : good 
  Wind  (km/h)                      : 20
  Temperature (deg C / humid.)      : 12 deg C
  Star image stability              : good 
  Minor planet visible              : yes
  Local conditions (degree)         : star height: 40, sun height: -49, 
  Local moon conditions (degree)    : moon height: below horizon

 8 ADDITIONAL COMMENTS:
  Star magnitude                          : 13.4
  Minor planet magnitude                  : 15.9
  Feed                                    : IBEROC
  Distance (km)                           : 3 km
  Faintest star on CCD (mag)              : 14.0
 
  A surprising single frame positive, due to long readout (1.4s) and exposure (1.5s) times. 
  A drop of 0.9 mag (vs. 2.6 predicted), suggesting the event during the exposure time. 
  Location just 3 km from the center line, but huge uncertainty (path width 24 km, sigma width 170km). 
  Probability 13.0%. 
  Just one point event, so classified as uncertain.