+--------------------------------+ +--------------------------------+ ASTEROIDAL OCCULTATION - REPORT FORM +--------------------------------+ +--------------------------------+ EAON & IOTA-ES EUROPEAN ASTEROIDAL OCCULTATION NETWORK INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION +--------------------------------+ +--------------------------------+ 1. DATE: 19 Jul 2020 STAR: UCAC4 363-088756 ASTEROID: (1646) Rosseland 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 : 19:56:00 -D : 19:59:06.18 ± 0.09 s -R : 19:59:07.80 ± 0.09 s -E : 20:02:00 Duration: 1.62 s ± 0.18 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, sensor uncooled, camera bit depth = MONO16, pixel image size = 960x600, USB traffic = 5, setted exposure = 60 ms, gain = 337, offset = 0, contrast = 0, brightness = 0, gamma = 1, banding suppression = 0, banding Threshold = 35 -Timekeeping: GPS UTC clock -Integration time: 0.060 s 7. OBSERVING CONDITIONS -Atmospheric transparency: good -Wind: none -Star image stability: fair -Minor Planet visible during the occultation: no 8. ADDITIONAL COMMENTS Prediction: -Occultwatcher, ITALOccult feed -Rank: 29 -Probability: 11.5 % -Combined magnitude: 11.9 mag -Star magnitude: 11.9 mag V; 11.4 mag R -Asteroid magnitude: 15.9 mag -Lightdrop: 4.0 mag; 4.1 mag R -Max duration: 1.8 s -Event time: 19:59:09 UT -Error in time: 4 s -Moon distance: - -Moon illumination: - Other comments: -Target sky position: elevation = 25 deg, azimut = 164 deg -Tangra v. 3.7.3 was used to generate the lightcurve (aperture photometry, average background) with 3 frames integration in "stepped averaging" mode -D and R times were manually evaluated -Measured mid-event UT time = 19:59:07.0 -A lightcurve can be seen here: http://sposetti.ch/wp-content/uploads/2020/08/2020_07_19_Rosseland_Gnosca_3.png