ASTEROIDAL OCCULTATION - REPORT FORM +----------------------------------------+ +----------------------------------------------+ | EAON | | IOTA/ES | | | | INTERNATIONAL OCCULTATION | | EUROPEAN ASTEROIDAL | | TIMING ASSOCIATION | | OCCULTATION NETWORK | | EUROPEAN SECTION | +----------------------------------------+ +----------------------------------------------+ 1 DATE: 2021 Jul 18 STAR : UCAC4 374-087705 ASTEROID: (11427) Willemkolff 2 OBSERVER: Name: Gérard VAUDESCAL Abbr:VDC E-mail: gg.vaudescal@free.fr Address: 65380 Azereix - France 3 OBSERVING STATION: Nearest city: AZEREIX (65380) Station: Observatoire d'Azereix Latitude: N 43 12 35.4 (WGS84) Longitude: W 00 00 46.4 (WGS84) Altitude: 340 m Single, OR Double or Multiple station (Specify observer's name): Single +---------------------------------------------------+ 4 TIMING OF EVENTS: | | | OCCULTATION RECORDED: NEGATIVE | | | +---------------------------------------------------+ Type of event Start observation Interrupt-start Disappearance Blink Flash End observation Jnterrupt-end Reappearance Other (specify) Event Time (UT) Acc. Comments Code HH MM SS.ss S.ss S - 22:05:42.22 on frame n°7 (time Tangra) D - +/- R - +/- E - 22:08:09.75 on frame n°427 idem Duration : sec xxxx +/- Mid-event: xxxxx (Pédicted 22:06:56 +/- 7,2 sec UT) Was your reaction time applied to the above timings? NO 5 TELESCOPE: Type: Ritchey Chrétien RC10 - Aperture: 254 mm - Magnification: Focus 2000mm - F/D=7.87 Mount: Equatorial - Motor drive: YES 6 TIMING & RECORDING: Time source: GPS 1 PPS - NMEA date/time Sensor: CAMERA ZWO ASI174MM Cool- Binning x2 - Exposition : 0,351sec/f =>2,85 fps Gamma na - Gain 400/400 - Black 18 Recording: Genika Mode 10bits - Vidéo SER8 Time insertion: module GPS_DCD_Time (Genika)-Synchronisation times UTC/frames with module SER Toolbox (Génika) Event insertion (specify): PC-Windows10 7 OBSERVING CONDITIONS: SKY: clear Cloud : 20% Wind: < 2 ms Temperature: 20°C Star image stability: seeing 1,5 arcsec Minor planet visible: No 8 ADDITIONAL COMMENTS: Reduction under TANGRA 3.7.3 Rev 20200512 Predicted Max Duration: 1.6 sec Predicted Magnitude Drop: 4.3 mag No corrections applied / the test results show a variation of +/- 10ms whatever the exposure times between 20 and 700ms