ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 23 September 2018                   STAR: UCAC4 461_131617  

  ASTEROID: Lagerkvist                 N?: 2875


2 OBSERVER: Name:   Tim HAYMES          Abbr: TVH
            E-mail: xxxxxxxxxxxxxxxxxxxxxxxxxxxx
            Address: Knowl Hill Common, RG10 9YD, UK

3 OBSERVING STATION: Nearest city: READING
  Station:  Fixed
  Latitude: N 51 30 23".8
  Longitude:W 00 48 58".2
  Altitude: 75m
  Datum (WGS84 preferred): WGS84

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


                         +----------------------------------+
4 TIMING OF EVENTS:      |                                  |
                         | OCCULTATION RECORDED: POSITIVE ? |
                         |                                  |
                         +----------------------------------+
  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  - 2203:37s    -      -      :  at 25 fps
       -             -      -      :
    D  - 2204: 19.92 -    +/- 0.04 
    R  - 2204: 20.52 -    +/- 0.06
       -             -      -      :
    E  - 2206:30s    -      -      :
  
                          Duration : 0.60 +/-0.10
                         Mid-event : 2204h 20.22s


5 TELESCOPE: Type: NEWTONIAN Aperture:  300mm   Magnification: Prime focus F/4
             Mount:EQ6       Motor drive: Yes

6 TIMING & RECORDING:
  Time source:			GPSBOXSPRITE2-U 
  Sensor:			WATEC 910HX/RC (CCIR, Serial No: 01106)
  Recording:	                OccuRec ( x1 frame) Dazzle(HD)A2D converter (Pinnacle), W10 SSD
  Time  insertion (specify):	1 PPS
  Event insertion (specify):	TANGRA and AOTA analysis

7 OBSERVING CONDITIONS:         	
  Atmospheric transparency: Clear in Moonlight  Wind: 0-1 B    Temperature: + 6 C
  Star image stability:     Moderate         	Minor planet visible?     : No

8 ADDITIONAL COMMENTS:
  Unexpected event. There is a clear step dimming of the target star by about 0.3 mag. Full disappearance 
  was not obtained. The star remained visable. No step in the guide or comparison stars. This looks genuine.

  If so, the light curve suggests a minor companion of the star was occulted 21 sec after nominal mid prediction.
  Furthermore, an independent light curve from Mr Tickner also shows the same phenomenon within the same time frame +/- 1 sec

  Integration    : 0.04s
  Gain           : 41 dB
  Gamma          : 1.0 
  S/N(Tangra)    : 5
  Mag limit ~    : 11.9   

  Predicted Time : 23 Sep; 22:03:59 UT   +/- 4 sec
  Combined Mag   : 11.2
  Predicted drop : 5.2
  Max. Duration  : 1 sec
  OW Centre Dist.: 46 km
  OW Probability : 5.2%
  Shaddow Width  : 16 km
  Alt/Az         : 37° @150°
  Moon Alt       : 28°    ill: 99%   @  12d  Distance
  Constellation  : Pisces