ASTEROIDAL OCCULTATION - REPORT FORM

1 DATE: 28 July 2019                   STAR: UCAC4 343_133579  

  ASTEROID: Thekla                  N?: 586

2 OBSERVER: Name:   Tim HAYMES          Abbr:
            E-mail: ******
            Address: 3 Florence Villas, ******

3 OBSERVING STATION: Nearest city: MAIDENHEAD
  Station:  
  Latitude: N 51 30 ****
  Longitude:W 00 48 ****
  Altitude: **
  Datum (WGS84 preferred): WGS84

                         +----------------------------------+
4 TIMING OF EVENTS:      |                                  |
                         |  OCCULTATION RECORDED: POSITIVE  |
                         |                                  |
                         +----------------------------------+
  Type of event
  Start observation   Interrupt-start   Disappearance   Blink   Flash
  End observation     Jnterrupt-end     Reappearance    Other (specify)
                                                  
  Event   Time (UT)    P.E.   Acc.  			  Comments 
  Code   HH MM SS.ss   S.ss   S.ss
  
    S  - 2147: 00    -      -      : Recording at 16 frame integration
    I  - 2147: 01				Cloud  
    J  - 2147: 33				Cloud interuption ended (Start of analysis)
    D  - 2148: 37.07      +/- 0.96 
    R  - 2148: 45.07      +/- 0.64    
    E  - 2149: 55    -      -      :
  
                          Duration : 8.0 +/ 1.5
                         Mid-event : 2148 41 s


5 TELESCOPE: Type: SCHMIDT NEWT. Aperture:  203mm   Magnification: Prime focus F/4
             Mount:EQ6       Motor drive: Yes

6 TIMING & RECORDING:
  Time source:			 GPSBOXSPRITE2-U 
  Sensor:			      WATEC 910HX/RC  1/2 inch 752x582 array (8.6 x 8.3u)
  Recording:	                Digital tape: Sony TRV33E DV camcorder (video-in)
  Time  insertion (specify):	1 PPS with OCR.  No corrections made by TANGRA with AVI format.
  Event insertion (specify):	TANGRA+AOTA analysis [AVI with FIREwire Express Card and MS MovieMaker in W7] 

7 OBSERVING CONDITIONS:         	
  Atmospheric transparency: Poor 2/5   Wind: 0-1 B         Temperature: + 15C
  Star image stability: Moderate 3/5   Minor planet visible?     :  NO

8 ADDITIONAL REMARKS
  Low altitude. I didn't expect to detect the star. A lot of high cloud was present, but there was a brief improvement
  as the mid time approached. Initially the star was not there, but then it came into view on the recording. The drop was 
  not seen on the monitor because I was looking in the wrong spot, but the analysis was of the correct star by reference to
  the star map. The light curve is uneven but its clear an event did occur.  Time errors are large. 

  The AOTA analysis was on "signal only"  (no background). The data looks smoother.


  Integration    : 0.64s
  Gain (dB)      : 33 dB
  Gamma          : 1.0 
  S/N(Tangra)    : 3
  Mag limit ~    : At limit of useful detection about 13.3

  Predicted Time : 28 Jul; 21:48:33 UT   +/- 5 sec
  Combined Mag   : 13.0
  Predicted drop : 1.2
  Max. Duration  : 10 sec
  OW Centre Dist.: 26 km
  OW Probability : 59.6%
  Shaddow Width  : 267 km
  Alt/Az         : 17° @178°
  Moon Alt       : -17°    
  Constellation  : Sagittarius