+--------------------------------+ +--------------------------------+ ASTEROIDAL OCCULTATION - REPORT FORM +--------------------------------+ +--------------------------------+ EAON & IOTA-ES EUROPEAN ASTEROIDAL OCCULTATION NETWORK INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION +--------------------------------+ +--------------------------------+ 1. DATE: 15 Jul 2022 STAR: UCAC4 410-122578 ASTEROID: (339) Dorothea 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 - 20:25:00 D - 20:28:04.6 ± 0.4 sec R - 20:28:07.6 ± 0.4 sec E - 20:29:30 Duration: 3.0 ± 0.6 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. 4.0.8395 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 =200 ms, gain = 400, offset = 0, contrast = 0, brightness = 0, gamma = 1, banding suppression = 47, banding threshold = 40, apply flat = none, subtract dark = none -Timekeeping: GPS UTC clock -Integration time: 0.200 s 7. OBSERVING CONDITIONS -Atmospheric transparency: good -Wind: no -Star image stability: good -Minor Planet visible during the occultation: yes 8. ADDITIONAL COMMENTS Prediction: -Occultwatcher, IBEROC feed -Rank: 100 -Probability: 65.5 % -Combined magnitude: 12.9 mag -Star magnitude: 13.9 mag V; 13.5 mag R -Asteroid magnitude: 13.4 mag -Lightdrop: 0.53 mag; 0.5 mag R -Max duration: 4 s -Event time: 20:28:05 UT -Error in time: 3 s -Moon distance: - -Moon illumination: - -https://cloud.occultwatcher.net/event/560-339-274980-647492-U122578 Other comments: -Target sky position: elevation = 24 deg, azimut = 132 deg -Tangra v. 3.7.3 was used to generate the lightcurve (aperture photometry, average background). Time reference: Start Frame -Analysis performed by Eric Frappa with PyOTE -Measured mid-event time: 20:28:06.1 UT -The lightcurve can be seen here: http://sposetti.ch/wp-content/uploads/2022/07/2022_07_15_Dorothea_Gnosca.png