Earthmoon occults the multiple star system SAO 75673

Diagram created with Guide 8 from Bill J Gray

The reappearance of the multiple star system on the dark side of the moon was captured with my equipment on video with an accuracy of some milliseconds. Evaluation of the video was done later.

 

Observation report

Date                         Observer Position - Nonndorf             Observer
2007/09/29                   48°  47´  13.3"  North  (WGS84)          Gerhard Dangl
Star                         15°  14´  08.3"  East   (WGS84)          3830, Nonndorf 12
ZC 440 = SAO 75673           550m (MSL),      595.0m (WGS84)          AUSTRIA

TELESCOPE:
        Type: Newton
	Focal length: 1200mm
 	Aperture: 254 mm
	Magnification: video/primary focus/recorded field 1112" x 830"
	Mount: Equatorial EQ6 with EQMOD
	Motor drive: Yes

TIMING & RECORDING:
	Timekeeping: GPS 1PPS Garmin18 LVC + KIWI-OSD
        Sensor/Camera: WAT-902H2 Ultimate, CCIR, 1/2" Sony CCD-Sensor ICX419ALL
	Mode of recording: It=20ms (50 Img/s), Video CCIR, AVI, YUY2, Huffyuv,
	Device of recording: Xpert V-Stream Videograbber USB2.0, Notebook Harddisk
        Time insertion: KIWI-OSD 

OBSERVING CONDITIONS:
	Atmospheric transparency: thin moving clouds
	Wind: No 
	Star image stability: bad
	Temperature: 281 Kelvin (+08 deg Celsius)
	
ADDITIONAL COMMENTS:
	Predictions with Occult3.6
	Video evaluation accomblished with VirtualDub1.6.16 and Limovie0927
        Only clear glass filter (Astronomik) for CCD protection was used
        3-D position and timing with Garmin GPS18 LVC receiving 06 satellites
        Horizontal dilution of precision 1.4, geoidal separation 44.8m

Occultation Predictions for Nonndorf_10Zoll in September 2007
E.Long.   15 14  8.2   Lat.  48 47 13.5   Alt. 590m.   T.dia 254mm.   dMag 2.0

      day  Time   P   Star  Sp  Mag    % Elon Sun  Moon   CA   PA  VA  WA Libration   A   B   RV   Cct   R.A. (J2000)  Dec
 y  m  d  h  m  s      No  D       V  ill     Alt Alt Az   o    o   o   o   L    B   m/o m/o "/sec   o  h  m   s    o  m  s
07 09 29 19 46 51 R X 54005DA2  5.6   87- 137     19  79  71N 268 313 284 +3.4 -5.6 +0.1+1.4 .580 +158  2 59 12.7  21 20 24
   X 54005 is double :   5.5  5.2   1.40"   29.0
07 09 29 19 46 51 R     440SA2  4.7   87- 137     19  79  71N 268 313 284 +3.4 -5.6 +0.1+1.4 .580 +158  2 59 12.7  21 20 25
       440 = epsilon Arietis                       
       440 is triple :   5.2  5.5   1.40"  209.0 :   4.6 12.7  146"  191.0

Calculation and reappearance diagram of multiple star system SAO 75673

   65°   ... Position angle of moon movement - value from Guide8.
  158°   ... Contact angle between the normal to the lunar limb and the direction of
             moon movement - value from Occult3.6.
0.580"/s ... Velocity of moon movement relative to component A - value from Occult3.6.
0.611"/s ... Velocity of moon movement relative to component A  - value from Guide8.

  209°   ... Position angle of component B - value from Occult3.6.
 1.40"   ... Distance of component B - value from Occult3.6.

  191°   ... Position angle of component C - value from Occult3.6.
  146"   ... Distance of component C - value from Occult3.6.

0.870"   ... Distance of components B-A on moon limb, value determined by own calculation.
0.780"   ... Difference distance of components A-B in direction of moon movement,
             value determined by own calculation.

 1.35s   ... Theoretical time difference during reappearance between components B-A,
             calculated with moon velocity of Occult3.6.
 1.28s   ... Theoretical time difference during reappearance between components B-A,
             calculated with moon velocity of Guide8.

 1.24s   ... Real measurement value B-A evaluated from video recording with time insertion.

Table with results of video measurements Component B Start 19:46:52.023 (+/-10ms) UTC Component B 50% 19:46:52.043 (+/-10ms) UTC Component B Full 19:46:52.063 (+/-10ms) UTC Component A Start 19:46:53.273 (+/-10ms) UTC Component A 50% 19:46:53.283 (+/-10ms) UTC Component A Full 19:46:53.303 (+/-10ms) UTC Components B-A Delay 1.240 (+/-20ms)

Measurement data - Excel format 280KB

Diagram - Overview

Diagram - Detail

Video MPEG4 2.1MB

Diagrams created with Software Limovie0927 from Kazuhisa Miyashita.

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