ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 08 December 2020                   STAR: 3UC231-011079  

  ASTEROID: Comet Schwassmann-Wachmann 1                 N?: 29P


2 OBSERVER: Name:   Richard MILES          Abbr: RMI
            E-mail: rmiles.btee@btinternet.com
           

3 OBSERVING STATION: Golden Hill Obs. (MPC J77)  Nearest city: SHERBORNE
  Station:  Fixed
  Latitude: N 50 55 51".5
  Longitude:W 02 24 19".0
  Altitude: 80m
  Datum (WGS84 preferred): WGS84

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


                         +----------------------------------+
4 TIMING OF EVENTS:      |                                  |
                         |  OCCULTATION RECORDED: NEGATIVE  |
                         |                                  |
                         +----------------------------------+
  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  - 23 20 02    -      -      :
       -             -      -      :
    D  -             -      -      :
    R  -             -      -      :
       -             -      -      :
    E  - 23 27 58    -      -      :
  
                          Duration : 
                         Mid-event : 

  Was your reaction time applied to the above timings? N/A

5 TELESCOPE: Type: SCHMIDT-CASSEGRAIN Aperture:  355mm   Magnification: Prime focus F/8
             Mount: Paramount MEII       Motor drive: Yes

6 TIMING & RECORDING:
  Time source:                  Computer clock synchronised with Dimension 4
  Sensor:			SXV H694 integrating CCD camera
  Recording:			Computer harddisk (read/write interval = 0.75s)
                                Start time of exposure recorded to nearest 0.1s
  Time  insertion (specify):  
  Event insertion (specify):

7 OBSERVING CONDITIONS:
  Atmospheric transparency: Good     Wind: 5 km/s    Temperature: 4C
  Star image stability: 4/5          Minor planet visible: Yes

8 ADDITIONAL COMMENTS:
  A CCD frame integration time of 1.5s was used, which equated to the
electronic shutter open for 67% of time. The star was of R magnitude 14.7.
The pseudonucleus of the comet was R magnitude 16.2. Apparent motion on
the sky was 12.2 km/s. The observing location was about 370km south of the
nominal JPL ephemeris track but 700km south of a high-precision orbit
calculated by Mike Kretlow using Gaia DR2 astrometry of >550 2.0-m images.
The size of the comet nucleus from HST and Spitzer data is 59-71km across
Photometry used 4 reference stars all within 3.0' of the star.
The ensemble magnitude of the comparisons exhibited a standard deviation 
of 0.05 mag.  A total of 213 frames were recorded in which the star
brightness remained constant with a standard deviation of 0.06 mag and no
fade greater than 0.15 mag was observed during the entire monitoring
interval. 

2020 December 09 1700UT