Grazing star occultation by the Earthmoon on June 13, 2009
SAO 164408

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On June 13, 2009 at about 02h01 UTC the Earthmoon grazed the star SAO 164408 in a height of 26 degrees above the southeast horizon with the dark area of the moon northpol. Thereby the star was occulted and became visible several times by the moon mountaines and moon valleys on the moon horizon. Despite of ground fog 10 occultation events, with two of them gradual, could be recorded on video.


The earthmoon grazes the star SAO 164408
The earthmoon grazes the star SAO 164408
Diagram created with Guide 8 from Bill J Gray


The moon profil at the calculated graze point
The moon profil at graze point
Diagram created with Occult 4 from Dave Herald

This grazing star occultation on the dark moon area was captured with my equipment with a relative high accuracy of some milliseconds and evaluated later.

Diagram of equipmennt setup
Diagram of equipmennt setup


The path of the grazing star occultation runs cross through Europe
Occultation path in Europe


The calculation of the observation point was done in a self made table sheet
Calculation of the observation point


Position elevation and moon profil require a double parallel shifting of the observation point (OP)
Observation point west from Eulenbach
Correction of observation point = (-842m) + (-963m) = -1805m shift to the green line for 0m above sea level


Aerial image of the calculated observation place west from Eulenbach - in northern Woodquarter
Observation place west from Eulenbach
Observation position 48° 47´ 08.6" North, 15° 07´ 59.9" East


The observation place and all the region around was covered by ground fog
Observation place west from Eulenbach

Because of the high IR sensitivity of the WAT-902H2 Ultimate video camera the star SAO 164408 with +8.1mag could be hold visible on the moon limb. Overall 12 events were recorded during this grazing star occultation.

The ground fog was no problem for the WAT-902H2 Ultimate video camera
Observation place west from Eulenbach
Observations during dawn are often accompanied by ground fog
Observation place west from Eulenbach


Observation report

Date Observer Position - 3902 Eulenbach Observer 2009/06/13 48° 47´ 08.6" North (WGS84) Gerhard Dangl Star 15° 07´ 59.9" East (WGS84) 3830, Nonndorf 12 SAO 164408, +8.1mag 553m (MSL), 597m (WGS84) AUSTRIA
TELESCOPE: Type: Newton Focal length: 1200mm Aperture: 254 mm Magnification: video/primary focus/FOV 18.3'x13.7' (768x576, 1.43"x1.43" per pixel) 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: TIS DFG/USB2-lt Videograbber USB2.0, Notebook Harddisk Time insertion: KIWI-OSD OBSERVING CONDITIONS: Atmospheric transparency: fair (ground fog) Wind: No Star image stability: fair Temperature: 277 Kelvin (+04 deg Celsius) ADDITIONAL COMMENTS: Predictions with Occult4 WAT-902H2 Ultimate with manual cable gain control. Video evaluation accomblished with VirtualDub1.8.5 Only clear glass filter (Astronomik) for CCD protection was used 3-D position and timing with Garmin GPS18 LVC receiving 09 satellites, Horizontal dilution of precision 1.0 Geoidal separation 44.5m (Altitude 552.7MSL + 44.5 = 597.2 m in WGS84 datum) Position shift calculations: Correction for MSL 517m: - 842 meters (path calculated for Mean Sea Level=0m) Correction for profile : -963 meters Observation point (OP) : -1805 meters

Table with precalculations prepared with Occult 4 from Dave Herald
Grazing Occultations near Nonndorf_0m_25cm, Austria
E. Longitude   15 14  8.4,  Latitude  48 47 13.5,  Alt.    0m;  Telescope dia 25cm;  dMag 0.0

       day  Time   P   Star  Sp  Mag  Mag    % Elon Sun Moon      Cusp angle   Distance       Azimuth    Path formula
 y   m  d  h  m  s      No  D     v    r V  ill     Alt Alt               o          km 
09 Jun 13  2  1 15 Gr 164408 K0  8.1  7.5   77- 122  -7 26 ** GRAZE: CA 12.4N; Dist.  8km in az. 303deg. [Lat =48.92+1.01(E.Long-15.24)]

Table with results of the video measurement

Phenomen       Cause       hh:mm:ss.sss   UTC second of date      Comment
Video start                01:59:29.071   7169.071                First video frame

D1             moon limb   02:00:42.391   7242.391                (+/- 20ms)
R1             moon limb   02:00:49.311   7249.311                (+/- 20ms)

D2             moon limb   02:01:06.390   7266.390                (+/- 20ms)
R2             moon limb   02:01:15.670   7275.670                (+/- 20ms) (smaller maximum of only 39% like R3 and R4 step)

D3             moon limb   02:01:15.870   7275.870                (+/- 20ms)
R3             moon limb   02:01:18.030   7278.030                (+/- 20ms) (gradual, fainter component)
R3             moon limb   02:01:18.270   7278.270                (+/- 20ms) (gradual, brighter component)

D4             moon limb   02:01:18.630   7278.630                (+/- 20ms)
R4             moon limb   02:01:27.470   7287.470                (+/- 20ms) (gradual, fainter component)
R4             moon limb   02:01:27.590   7287.590                (+/- 20ms) (gradual, brighter component)

D5             moon limb   02:01:29.230   7289.230                (+/- 20ms)
R5             moon limb   02:01:56.150   7316.150                (+/- 20ms) (in video no step)

Video end                  02:02:31.629   7351.629                Last video frame

Diagram of all events
Diagram of all events
Diagram D1
Diagram D1

Video D1
Video D1 - MPEG4 1.34MB
MPEG4 1.34MB

Diagram R1
Diagram R1

Video R1
Video R1 - MPEG4 1.31MB
MPEG4 1.31MB

Diagram D2
Diagram D2

Video D2
Video D2 - MPEG4 1.35MB
MPEG4 1.35MB

Diagram R2, D3
Diagram R2, D3

Video R2, D3
Video R2, D3 - MPEG4 1.54MB
MPEG4 1.54MB

Diagram R3, D4
Diagram R3, D4

Video R3, D4
Video R3, D4 - MPEG4 2.1MB

Diagram R4, D5
Diagram R4, D5

Video R4, D5
Video R4, D5 - MPEG4 3.34MB
MPEG4 3.34MB

Diagram R5
Diagram R5

Video R5
Video R5 - MPEG4 1.51MB
MPEG4 1.51MB

Faint signal of SAO 164408 (39%)
Faint signal - SAO 164408 in R2/D3, R4 and R5
R2/D3, R4 and R5

A report with data of this measurements was created with Occult4 and transfered via email to the relevant autority in Japan for evaluation and further use.


The reduction of the measurement data to the moon profil
Reduction of the measurement data
Created with Occult 4 from Dave Herald

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October 19, 2009
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