+--------------------------------+ +--------------------------------+

ASTERIODAL OCCULTATION - REPORT FORM

+--------------------------------+ +--------------------------------+

EAON & IOTA-ES

EUROPEAN ASTEROIDAL OCCULTATION NETWORK

INTERNATIONAL OCCULTATION TIMING ASSOCIATION EUROPEAN SECTION

+--------------------------------+ +--------------------------------+

1. DATE: 03 Jan 2019
   STAR: UCAC4 418-150499
   ASTEROID: (137) Meliboea

2. OBSERVER
   
   Name: Stefano SPOSETTI
   Address: 6525 GNOSCA - Switzerland
   Email: stefanosposetti@ticino.com

3. OBSERVING STATION
   
   Nearest city: CH-6600 Locarno
   Station: Specola Solare
   Longitude (DD MM SS.s): 08 47 16.0 E
   Latitude (DD MM SS.s): 46 10 20.1 N
   Altitude: 368 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 : 18:27:10
-D : 18:29:10.30 ± 0.32 s
-R : 18:29:12.22 ± 0.32 s
-E : 18:31:30

   Duration: 1.92 s ± 0.64 s

5. TELESCOPE
   Type: Schmidt-Cassegrain, Celestron 8-inch
   Aperture: 200 mm
   Focal length: 900 mm (with focal reducer)
   Magnification: -
   Mount: Equatorial
   Motor drive: Yes

6. TIMING & RECORDING
   -Camera/Sensor: Videocamera WAT-910HX-RC, CCIR, 1/2", ICX429ALL sensor
   -Videocamera settings: Shutter = x32; Gain = 41/41; Gamma = 1.00
   -Device of recording: Personal computer
   -Grabber: Imaging Source DFG/SV1 PCI, composite input
   -Software: Virtualdub v. 1.10.4, saved on Harddisk as Lagarith compressed file

   -Time insertion device: IOTA-VTI, v.1.1.42
   -Timekeeping: GPS 1PPS (US Global Sat EM-406A)
   -Integration time: 0.640 s
  
7. OBSERVING CONDITIONS
   
   -Atmospheric transparency: good
   -Wind: none in the observatory
   -Star image stability: very bad, strong turbulence
   -Minor Planet visible during the occultation: no

8. ADDITIONAL COMMENTS
   
   Prediction:
   -Occultwatcher, IOTA feed
   -Rank: 100
   -Probability: 100 %
   -Combined magnitude: 11.8 mag
   -Star magnitude: 11.8 magV; 11.0 magR
   -Asteroid magnitude: 13.4 mag
   -Lightdrop: 1.8 mag; 2.1 magR
   -Max duration: 3.5 s
   -Event time: -
   -Error in time: 1 s
   -Moon distance: -
   -Moon illumination: none

   Other comments:
   -Sky position of the target: elevation = 13 deg, azimut = 246 deg
   -Because of bad recording hardware the two fields were wrongly added together. Virtualdub was used during analysis to deinterlace the fields and to reassemble the frames in the right sequence
   -Tangra v. 3.6.18 was used to generate the lightcurve (aperture photometry, average background)
   -S/N of the target (before D and after R) about 6
   -Measured lightdrop: none
   -A correction of -0.340 s was applied because of the use of an integration camera (so called "Dangl-correction")
   -A lightcurve can be seen here:
http://sposetti.ch/wp-content/uploads/2019/01/2019_01_03_Meliboea_Locarno.png