ASTEROIDAL OCCULTATION - REPORT FORM

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

1 DATE: 5 September 2010                   STAR: HIP 1927 
  ASTEROID:                  N: 474 Prudentia

2 OBSERVER: Name:   Costantino SIGISMONDI          Abbr: 
            E-mail: sigismondi@icra.it
            Address: via Sesto Celere 6, 00152 Rome ITALY
3 OBSERVING STATION: Nearest city: ROME
  Station:  Fixed
  Latitude:     N 41° 52' 44".6
  Longitude:  E  12° 27' 07".7
  Altitude: 66 m
  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)

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                                                  Comments

Without a suitable video-recording apparatus (all suitable for the Sun...) I decided to make an audio record, with time insertion given by BeeperSync beeps. This audio file is available on my web page at www.icra.it/solar
The declared accuracy of 0.01s  is that one of repering timing from audio file (with software Audacity 1.3 beta); the reaction time appliyed 0.24 s is a reliable standard -not personal- value. 
The duration of about one second was clear to me, instead of a maximum duration 5.5 seconds for the predicted centerline were I was. 
The disappearance occurred in the second without time signal before the minute signal given by BeeperSync. 
(see http://hristopavlov.net/BeeperSync/)
The star (RA 0:24:53 DEC -1:10:41) was unambiguously identified thanks to its coordinates which were different from Jupiter (RA 0:04:24.1  DEC -1:13:27 ) by 3 arcminutes in declination and 20m30s in r.a. therefore I pointed Jupiter and I waited 20m30s to have the star in the center of the field of view, with no motor drive. The star was just after the meridian, so the altazimuth mount was enough to follow it using only the azimuth by hand. 
___________________________________________________________________________

  Event   Time (UT)    P.E.   Acc.  
  Code   HH MM SS.ss   S.ss   S.ss
 
    S  - 01 14  30     -      -      :
       -             -      -      :
    D  -01 15 59.04        0.24  -     0.01 -      :
    R  -01 16 00.17        0.24  -     0.01-      :
       -             -      -      :
    E  - 01 16 30     -      -      :
 
                          Duration : 1.13
                         Mid-event : 1.13
  Was your reaction time applied to the above timings? YES
5 TELESCOPE: Type: SCHMIDT-CASSEGRAIN Aperture:  203mm F/10  Magnification: 80x (eyepiece KE 25mm)
             Mount: Altazimuth       Motor drive: No
6 TIMING & RECORDING:
  Time source:   Internet-USNO-BeeperSync 
  Sensor:          naked eye
  Recording:      audio Creative MuVo TX 8kHz 4 bit 
  Time  insertion (specify): BeeperSync
  Event insertion (specify): voice
7 OBSERVING CONDITIONS:
  Atmospheric transparency: Good   Wind: 0   Temperature: 20 °C
  Star image stability: OK     Minor planet visible: No
 
8 ADDITIONAL COMMENTS:
Disappearance and reappearance were sudden, I did not perceive a slow decrease of the stellar luminosity  event like in 472 Roma occultation recorded by Jan Manek ( http://www.youtube.com/watch?v=1XEdR0B-pGA ).
In any case I was surprised by the shortness of this event, which is my second succesfull asteroidal occultation after that one of Rhodope over Regulus of 19 oct 2005, the first observed from home. 
Finally it is remarkable that the longitude of my observing station (kitchen's balcony) is that one of the first italian meridian, passing through Monte Mario Observatory and the dome of St. Peter's basilica.