1 DATE : 12/DEC/2004
 STAR : TYC 0144-01868-1
 ASTEROID : (85) IO

2.OBSERVER:
Name: Stefano SPOSETTI
Address: CH-6525 Gnosca, Switzerland
E-mail: stefanosposetti@freesurf.ch

3.OBSERVING STATION:
Nearest city: CH-6500 Bellinzona
Station: Gnosca Observatory
Latitude: 46deg 13min 54sec (N)
Longitude: 9deg 1min 30sec (E)
Altitude: 260 m
Single/Multiple: single

5.TELESCOPE:
Type: Newtonian
Aperture: 40cm
Magnification: -
Mount: equatorial
Motor drive: yes

6.TIMING & RECORDING:
        Occultation recorded:   POSITIVE
        Personal Equation Substracted: No
        Event Time in UT
        Code:           HH:MM:SS.ss  S.ss
        S              21:01:54,2
        D              21:05:41.5     ± 1s
        R              21:05:55.5    ± 1s
        E              21:11:03,5
Duration of the occultation: 14,0 +- 0,2s

Timekeeping: via Computer thru "Dimension4" software.
Mode of recording: CCD drift-scan thru "Winscan 207" software.
Device of recording: SBIG ST8 CCD

7.OBSERVING CONDITIONS:
Atmospheric transparency: good
Wind: no
Star image stability: good
Temperature: 0 deg C

8.ADDITIONAL COMMENTS:
The accuracy of the absolute time measurement is +-1sec.
The accuracy of the duration of the occultation is +- 0,2s
While I'm quite confident of the accuracy of the duration of the occultation,
it was quite difficult to determine the absolute timings ot the start and the
end of the occultation.
I can provide an selected image of the drift-scan.