+--------------------------------+ +--------------------------------+

ASTEROIDAL OCCULTATION - REPORT FORM

+--------------------------------+ +--------------------------------+

EAON & IOTA-ES

EUROPEAN ASTEROIDAL OCCULTATION NETWORK

INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION

+--------------------------------+ +--------------------------------+

1. DATE: 16 Jan 2020
   STAR: UCAC4 564-015416
   ASTEROID: (2058) Roka

2. OBSERVER
   Name: Stefano SPOSETTI
   Address: 6525 GNOSCA - Switzerland
   Email: stefanosposetti@ticino.com

3. OBSERVING STATION
   Nearest city: CH-6525 Gnosca
   Station: 143 (MPC-code)
   Longitude (DD MM SS.s): 09 01 26.5 (E)
   Latitude (DD MM SS.s): 46 13 53.2 (N)
   Altitude: 260 m
   (WGS84)

4. TIMING OF EVENTS
   Occultation recorded: POSITIVE
   Type of event:
   "S"tart observation;
   "I"nterrupt-start;
   "D"isappearance;
   "B"link;
   "F"lash;
   "E"nd observation;
   "I"nterrupt-end;
   "R"eappearance;
   "O"ther (specify)

   Personal Equation Substracted: -
   Event Time (UTC) Accuracy + Comments
   code: HH:MM:SS.ss S.sss

-S : 21:05:15
-D : 21:07:09.725 ± 0.075 s
-R : 21:07:12.651 ± 0.075 s
-E : 21:09:15

   Duration: 2.93 s ± 0.15 s

5. TELESCOPE
   -Type: Newton
   -Aperture: 420 mm
   -Focal length: 1640 mm
   -Mount: Equatorial
   -Motor drive: Yes

6. TIMING & RECORDING
   -Camera/Sensor: Videocamera  QHY174M-GPS, SONY IMX174 CMOS sensor
   -Device of recording: Personal computer, USB3 input, SharpCap PRO v. 3.2.6173.0 software, saved on SSD as SER file
   -binning = 2x2, uncooled, camera bit depth = 8, pixel image size = 976 x 611, USB Traffic = 0, setted exposure = 150 ms, Gain = 480, Offset = 0, Contrast = 0, Brightness = 0, Gamma = 1
   -Timekeeping: GPS UTC clock
   -Integration time: 0.150 s
  
7. OBSERVING CONDITIONS
   
   -Atmospheric transparency: good
   -Wind: none 
   -Star image stability: good
   -Minor Planet visible during the occultation: no

8. ADDITIONAL COMMENTS
   Prediction:
   -Occultwatcher, IBEROC feed
   -Rank: 33
   -Probability: 0.0 %
   -Combined magnitude: 13.9 mag
   -Star magnitude: 14.0 mag V; 13.3 mag R
   -Asteroid magnitude: 17.1 mag
   -Lightdrop: 3.16 mag; 3.4 mag R
   -Max duration: 2.2 s
   -Event time: 21:07:08 UT
   -Error in time: 5 s
   -Moon distance: -
   -Moon illumination: -
 
   Other comments:
   -Target sky position: elevation = 67 deg, azimut = 182 deg
   -Tangra v. 3.6.22 was used to generate the lightcurve (aperture photometry, average background)
   -Time reference used in Tangra: end frame, because of successive tests
   -S/N ratio ~ 7 during pre- and after- event
   -Signal dropped from ~ 650 ADU to ~ 0 ADU
   -Measured mid-event UT time: 21:07:11.19
   -Accordingly to Occultwatcher my location was 181 km outside the 1-sigma zone
   -A lightcurve can be seen here:
http://sposetti.ch/wp-content/uploads/2020/02/2020_01_16_Roka_Gnosca.png