+--------------------------------+ +--------------------------------+ ASTEROIDAL OCCULTATION - REPORT FORM +--------------------------------+ +--------------------------------+ EAON & IOTA-ES EUROPEAN ASTEROIDAL OCCULTATION NETWORK INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION +--------------------------------+ +--------------------------------+ 1. DATE: 11 Sep 2022 STAR: UCAC4 479-129046 ASTEROID: (59592) 1999 JW58 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 - 20:11:00 D1 - 20:13:50.387 ± 0.010 sec R1 - 20:13:50.629 ± 0.010 sec D2 - 20:13:51.092 ± 0.010 sec R2 - 20:13:51.143 ± 0.010 sec E - 20:17:00 Duration 1: 0.242 ± 0.020 sec Duration 2: 0.051 ± 0.020 sec 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. 4.0.9268.0 software, saved on SSD as SER file -binning = 2x2, sensor cooled, sensor temperature = 0 °C, camera bit depth = MONO16, area size in pixel = 960x600, USB traffic = 5, setted exposure = 20 ms, gain = 480, offset = 0, contrast = 0, brightness = 0, gamma = 1, banding suppression = 40, banding threshold = 40, apply flat = none, subtract dark = none -Timekeeping: GPS UTC clock -Integration time: 0.020 s 7. OBSERVING CONDITIONS -Atmospheric transparency: good -Wind: no -Star image stability: fair/good -Minor Planet visible during the occultation: no 8. ADDITIONAL COMMENTS Prediction: -Occultwatcher, OWC -Rank: 8 -Probability: 4.4 % -Combined magnitude: 11.2 mag -Star magnitude: 11.2 mag V; 10.9 mag R -Asteroid magnitude: 19.3 mag -Lightdrop: 8.1 mag; 8.0 mag R -Max duration: 0.3 s -Event time: 20:13:47 UT -Error in time: 3 s -Moon distance: 40 deg -Moon illumination: 97 % -https://cloud.occultwatcher.net/event/618-59592-309810-648365-U129046 Other comments: -Target sky position: elevation = 44 deg, azimut = 142 deg -Tangra v. 3.7.3 was used to generate the lightcurve (aperture photometry, median background). Time reference: Start Frame -About 0.5 s after the principal reappearing (R1) a brief second occultation occured. This second event lasted two integration frames with a smaller lightdrop -Measured principal lightdrop: ~ 1.2 mag -Measured secondary lightdrop: ~ 0.6 mag -Many thanks to Eric Frappa who checked and refined the analysis -The lightcurve can be seen here: https://sposetti.ch/wp-content/uploads/2022/09/20220911_1999JW58_Gnosca.png