+--------------------------------+ +--------------------------------+ ASTERIODAL OCCULTATION - REPORT FORM +--------------------------------+ +--------------------------------+ EAON & IOTA-ES EUROPEAN ASTEROIDAL OCCULTATION NETWORK INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION +--------------------------------+ +--------------------------------+ 1. DATE: 23 Nov 2017 STAR: 4UC 523-003622 ASTEROID: (155) Scylla 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 : 20:43:11 -D : 20:51:38.18 ± 0.04 s -R : 20:51:42.58 ± 0.04 s -E : 20:57:00 Duration: 4.40 s ± 0.08 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 = x4; Gain = 38/41; 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: 0.080 s 7. OBSERVING CONDITIONS -Atmospheric transparency: fair/good -Wind: none -Star image stability: good -Minor planet visible during the occultation: barely 8. ADDITIONAL COMMENTS -Target position: elevation = 58 deg; azimut = 166 deg; Accordingly to Occultwatcher prediction, IBEROC feed: -Rank: 87 -Probability: 9.3 % -Combined magnitude: 12.6 mag -Star magnitude: 13.0 mag -Asteroid magnitude: 14.1 mag -Lightdrop: 1.3 - 1.7 mag -Max duration: 6.3 s -Event time: 20:51:33 UT -Error in time: 4 s -Moon: under the horizon -Moon illumination: none -Tangra v. 3.6 was used to generate the lightcurve (aperture photometry, average background). -A correction of -0.060 s was applied because of the use of an integration camera. -A lightcurve can be seen here: http://sposetti.ch/wp-content/uploads/2014/09/2017_11_23_Scylla.png