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

ASTERIODAL OCCULTATION - REPORT FORM

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

EAON & IOTA-ES

EUROPEAN ASTEROIDAL OCCULTATION NETWORK

INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION

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

1. DATE: 28 Jan 2018
   STAR: 4UC 593-005847
   ASTEROID: (84522) 2002 TC302

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

3. OBSERVING STATION
   Nearest city: CH-6525 Gnosca
   Longitude: 9d 1m 26.5s (E)
   Latitude: 46d 13m 53.2s (N)
   Altitude: 260m
   (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 : 21:41:20
-D : 21:52:34.72 ± 2.56 s
-R : 21:54:18.40 ± 1.28 s
-E : 22:05:25

   Duration: 103.68 s ± 3.84 s

5. TELESCOPE
   -Type: Schmidt-Cassegrain, Celestron 11-inch
   -Aperture: 280 mm
   -Focal length: 930 mm (with focal reducer)
   -Magnification: FOV 23x18 arcmin
   -Mount: Equatorial
   -Motor drive: Yes

6. TIMING & RECORDING
   -Sensor/Camera: Videocamera WAT-910HX-RC, CCIR, 1/2", ICX429ALL sensor
   -Videocamera settings: Shutter = x128; Gain = 26/41; Gamma = 1.00
   -Device of recording: Personal computer, Imaging Source DFG/SV1 PCI, composite input, Virtualdub acquiring software, saved on Harddisk as uncompressed file
   -Timekeeping: GPS 1PPS (US Global Sat EM-406A)
   -Time insertion device: IOTA-VTI, v.1.1.42
   -Integration time: 2.560 s
  
7. OBSERVING CONDITIONS
   -Atmospheric transparency: good
   -Wind: none 
   -Star image stability: good
   -Minor Planet Visible during the occultation: no

8. ADDITIONAL COMMENTS
   -Target position: elevation = 34 deg; azimut = 277 deg.
   
   Accordingly to Occultwatcher prediction, RIO-TNO feed:
   -Rank: 35
   -Probability: 20.2 %
   -Combined magnitude: 15.4 mag
   -Star magnitude: 15.4 mag
   -Asteroid magnitude: 20.6 mag
   -Lightdrop: 5.21 mag; 7.2 magR
   -Max duration: 122.2 s
   -Event time: 21:55:22 UT
   -Error in time: 3.9 min
   -Moon distance: 52 deg
   -Moon phase: 90 %

   -The transparency of the sky was good. The moonlight illuminated the landscape and the interior of the observatory (roll-off roof was open).
   -The target star was only visible with an integration time of 2.56 s and a (low) gain of 26/41. That setup resulted in a low (but measurable) SNR between 5 and 10. With a lower integration time (i.e. 1.280 s) the target was not visible.
   -Tangra v. 3.6.15 was used to generate the lightcurve (aperture photometry, average background).
   -The disappearance instant seemed not so evident as the reappearance, therefore a greater tolerance was applied.
   -During the recording process Virtualdub inserted some frames but not during the occultation interval.
   -A correction of -1.300 s was applied because of the use of an integration camera.
   -A binned lightcurve can be seen here:
http://sposetti.ch/wp-content/uploads/2018/02/20180128_84522_2002TC302.png