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ASTEROIDAL OCCULTATION - REPORT FORM

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EAON & IOTA-ES

EUROPEAN ASTEROIDAL OCCULTATION NETWORK

INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION

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1. DATE: 26 Mar 2022
   STAR: UCAC4 590-037794
   ASTEROID: (19665) 1999 RT137

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 : 22:38:30
-D : 22:41:30.70 ± 0.08 s
-R : 22:41:31.15 ± 0.08 s
-E : 22:44:30

   Duration: 0.45 ± 0.16  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. 4.0.8395 software, saved on SSD as SER file
   -binning = 2x2, sensor uncooled, camera bit depth = MONO16, area size in pixel = 960x600, USB traffic = 5, setted exposure =150 ms, gain = 480, offset = 0, contrast = 0, brightness = 0, gamma = 1, banding suppression = 36, banding threshold = 40, apply flat = none, subtract dark = none
   -Timekeeping: GPS UTC clock
   -Integration time: 0.150 s

7. OBSERVING CONDITIONS
   
   -Atmospheric transparency: fair
   -Wind: no 
   -Star image stability: good
   -Minor Planet visible during the occultation: no

8. ADDITIONAL COMMENTS
   
   Prediction:
   -Occultwatcher, UKOCL feed
   -Rank: 64
   -Probability: 39.7 %
   -Combined magnitude: 13.0 mag
   -Star magnitude: 13.0 mag V; 12.8 mag R
   -Asteroid magnitude: 18.5 mag
   -Lightdrop: 5.5 mag; 5.2 mag R
   -Max duration: 0.7 s
   -Event time: 22:41:31 UT
   -Error in time: 2 s
   -Moon distance: -
   -Moon illumination: -

   Other comments:
   -Target sky position: elevation = 34 deg, azimut = 276 deg
   -Tangra v. 3.7.3 was used to generate the lightcurve (aperture photometry, average background). Time reference: Start Frame 
   -AOTA v4.12.16.0 was used to calculate D and R times and uncertainties 
   -Measured lightdrop: -
   -Eric Frappa checked the results
   -Measured mid-event time: 22:41:30.9 UT   
   -The lightcurve can be seen here:
http://sposetti.ch/wp-content/uploads/2022/03/2022_03_26_19665_Gnosca.png