Observations Grazing Occultation Triple Star - 2004 September 6

Co-ordinator: Bertrand Thooris, AstroLAB IRIS, Ieper, Belgium
Last updated 20:15 3/10/2004
This website is maintained by Philippe Vercoutter, AstroLAB IRIS, Ieper, Belgium

Part 1 - Event Data:

Place : Rekkem (Menen)
Time : 02h 29m UT
Triple Star : 62 Taurus (XZ 5680)
Magnitude : 6.35
Altitude of the star : 49°
Altitude of the Sun : -23°
P.A. : 337°
C.A. : 13.4° North limit ( dark limb)
Azimuth : 115°
Illumination of the Moon : 55% (decreasing phase)
Minimum aperture for this observation : 11,5 cm
Henk Bulder produced this chart using the WinOccult software.

Part 2 - Documents:

  • Overview of all the Belgian grazing occultations in 2004 (APEX)
  • Geographical overview of the grazing occultation
  • Limb Profile 1 (© 2004 by APEX)
  • Limb Profile 2 (© 2004 by APEX)
  • Map of observation sites (the numbers on the map are not always the same numbers as they were used in the field, so use the GPS data below for data reductions)
  • Aerophoto of observation sites (by Johan Vanbeselaere)
    Background articles about the treatment of geographic coordinates:
  • Conversion de coordonées géodésique (by Jean Schwaenen, PDF, 2.3 MB)
  • Wo bin ich ? (IOTA-ES, in German, PDF, 329 KB, HTML version)



    Philippe Vercoutter captured the event using a Philips ToUCam webcam. This footage was treated using special software so that a duration accuracy of 67 milliseconds could be achieved.
    Component B of 62 Tauri, a small star of the 8th magnitude, could also be seen and captured at moments of better seeing.



    Although an announcement was made that at least a 115mm telescope would be necessary, Christian Verkouter was able to follow and capture the whole grazing occulation with a 90 mm Helios refractor.
    Jessica Bulder at her observation site in Buinerveen, The Netherlands.

    Part 3 - Observers & Observations:

    See also the results made by an observer team in the Netherlands:
  • Official report by Henk & Jessica Bulder observing from Buinerveen
  • Map of their observation sites
  • Graphical Reduction of the Results

    Overview of the Belgian results:


  • Jean Schwaenen produced a table of all results (as used by him in his reductions).
  • Henk Bulder made a comparison between the ED50 and WGS84 coordinates of the observers (MS Word document).

    Location Observer GPS (WGS84)
    # sub occultations
    		 Video & Webcam Results Telescope Clock & Timings (all times in UT)
    1 Edwin De Ceuninck GPS (1)
    1
    Video not available yet.
    		 Helios 90 mm F=900mm DCF-77 - Sound on Video
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    ? ?
    3.17
    2 Jean Lheureux GPS (1)
     
    		      
    3Bis Geert Vandenbulcke GPS (1)
    2 or 3
    Images were not captured.
    		 STF 180 mm f/10 Maksutov Cassegrain DCF-77 - Visual
    Read Geert's Official Report
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    2h 28m 23.45s 2h 28m 28.47s
    5.02
    13.57
    2h 28m 42.04s 2h 29m 24.04s
    42.00
    Geert reports also a blink phenomenon at 2h 28m 40.45s.
    HQ Jean Schwaenen GPS (1)
     
    		      
    5 Patrick Degrelle Lat. N 50° 45' 42,6"
    Long. E 003° 10' 22,9"
    Alt. 28m
    GPS (WGS84)
    2
    Images were not captured.
    		 Newton F/D 5 D=153mm - 130 X DCF 77.5 on Audio Tape
    Read Patrick's Official Report
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    2h 28m 16.25s 2h 29m 49.8s
    93.55
    44.6
    2h 30m 34.4s 2h 30m 38.7s
    4.3
    6 Bertrand Thooris GPS (1)
    2
    		 SONY EXview HAD CCD Camera 2005 XA was used.

    Video not available yet.
    		 Lichtenknecker AFK 125/750 DCF-77 & Cuno Time Inserter
    Read Bertrand's Official Report
    Accuracy: +/- 0.04s
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    2h 27m 57.22s 2h 29m 52.20s
    114.98
    40.09
    2h 30m 32.29s 2h 30m 41.27s
    8.98
    6Bis Patrick Hamptaux
    Julien Quenard    		 GPS (1)
    4
    		 Webcam not used
    (due to technical problems).    		 Celestron C8 with 9mm eye-piece Stopwatch - Visual
    Accuracy: +/- 1s
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    *** 2h 29m 51s
    ***
    ***
    2h 30m 31s ***
    ***
    ***
    2h 30m 54s 2h 31m 02s
    8
    42
    2h 31m 44s 2h 31m 55s
    11
    (***) This timing could not be recorded or derived.
    7Bis Christian Verkouter
    Philippe Vercoutter    		 GPS (1)
    5
    		 Webcam (69 MB) Helios 90 mm F=900mm Atomic Clock (Internet)
    Absolute Accuracy: +/- 1s
    Duration Accuracy: +/- 1/15s = 0.067s
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    2h 27m 43s 2h 29m 54s
    131.200
    1.800
    2h 29m 56s 2h 30m 03s
    7.000
    4.266
    2h 30m 08s 2h 30m 09s
    1.600
    ***
    *** 2h 30m 47s
    ***
    2.667
    2h 30m 50s 2h 31m 06s
    15.600
    (***) One duration could not be determined due to a problem with the image framing. The contact time was at least equal to 2h 30m 25s.
    7 Johan Vanbeselaere GPS (1)
    5
    		 Video not available yet. Helios 90 mm F=900mm DCF-77 & Cuno Time Inserter
    STAR OFF STAR ON DURATION OFF
    in seconds    		 DURATION ON
    in seconds
    2h 27m 44s 2h 29m 54s
    130
    3
    2h 29m 57s 2h 30m 03s
    6
    5
    2h 30m 08s 2h 30m 09s
    1
    20.5
    2h 30m 29.5s 2h 30m 47s
    17.5
    3.5
    2h 30m 50.5s 2h 31m 5.5s
    15

    (1) The GPS data were collected using an EMTAC Bluetooth GPS and a PC running VisualGPS. At least 200 sample data per location were collected and averaged.

    Part 4 - Results:

    Graphical reductions by Jean Schwaenen.
    Jean uses the (older) Watt profiles and the Capron theory.



    The data reductions below were performed by Henk Bulder, The Netherlands.
    Henk uses the predictions from GrazeReg (IOTA-ES). The dotted line represents Watts profile whereas the solid line represents the Aclppp profile.
    Read more on the IOTA-ES website.





    Geert Vandenbulcke also derived a resulting Moon profile (see the red line in the graph below).





    © 2004 by AstroLAB IRIS, ACG vzw, Belgium