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On the morning of 11 December 2006 at about 05h49 UTC the earthmoon grazed and occulted the star ZC 1522 = SAO 99098, assigned to spectralclass K0, with the dark southern limb. The star in a distance of around 750 lightyears shines 84 times brighter as our sun does and the visuell brightness is +6.8mag. The waning moon was lit to 63 percent and his position was 46 degrees above the southwest horizon.
The calculation of this grazing star occultation was done with the excellent software Occult3.6 from Dave Herald. With this software one can search relevant events within a radius of a position. About the individual events tables with time- and position values can be generated. Additionally the software generates diagrams of the occultation sequence and of the affected moonlimb.
With the table values one can manually generate a path in a maping software. But this table values also can be used automatically by the excellent software Shadow from Geoff Hitchcox. This software generates several different files which can be used by different maping software products for path generating or can be used in GPS systems for the definition of position points. And for instance one can create also an occultation path in Google Earth with such a file.
After the path of a grazing occultation was created one should define a reasonable observation position with the use of a detail diagram of the moonlimb. Additionally this horizontal position is always addicted to the position height. Mostly several suitable observation positions on the path exist. The choice of the observation position will be made under considerations of reachability by car, local sight conditions and undisturbed observation possibility. But if the position is unknown or can not be checked before one should calculate several alternatives.
For this grazing star occultation a path for a nominal height of 530 meter was calculated. This height value is referenced to the World Geodetic System 1984 (WGS84). The Mean Sea Level (MSL) is about the value of the "Geoidal Separation" lower as the WGS84 value. In the "Waldviertel", in translation woodquarter, this difference averages about 44 meters.
The moonlimb diagram shows several ensured disappearances and reappearances of the star for positions lying around 1000 meters in moon direction from path. So I selected a good reachable position lying about 1000 meters from nominal path in direction southwest. This suitable position was about 600 meters northwards from the village "Obergrünbach" in northern woodquarter and could be reached by me after a 27 kilometers route within 30 minutes although glaze was on the streets.
The moon grazes during movement to the East with mountains and valleys on the limb the star SAO 99098
Graphic created with Guide 8 from Bill J Gray.Table with calculated data about star, moon and path (Occult3.6)
Occultation Predictions for Nonndorf in Dezember 2006 E.Long. 15 14 8.2 Lat. 48 47 13.5 Alt. 590m. T.dia 250mm. dMag 0.0 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 Graze of 1522 K0 nearby at Lat = +49.10 -0.98(E.Long -15.24), CA = 15.9S 11 5 49 5 Gr 1522 K0 6.8 63- 105 -8 46 219 Closest distance to graze path is 19km at azimuth 56 06 12 11 5 49 42 M 1522 K0 6.8 63- 105 -8 46 219 16S 217 192 197 +3.9 -1.3 +2.0+3.4 .208 -118 10 24 19.5 10 35 16 Grazing Occultation of 1522 K0 Magnitude 6.8 Date 2006 Dezember 11 (Montag) Nominal site altitude 530m E. Longit. Latitude U.T. Sun Moon TanZ PA WA CA o ' " o ' " h m s Alt Alt Az o o o 14 30 0 49 48 17 5 46 58 -9 46 216 0.97 216.9 197.23 15.76S 14 33 0 49 45 27 5 47 6 -9 46 217 0.97 216.9 197.24 15.77S 14 36 0 49 42 36 5 47 15 -9 46 217 0.97 216.9 197.25 15.78S 14 39 0 49 39 46 5 47 24 -9 46 217 0.97 216.9 197.26 15.78S 14 42 0 49 36 55 5 47 32 -9 46 217 0.97 216.9 197.27 15.79S 14 45 0 49 34 4 5 47 41 -9 46 217 0.97 217.0 197.28 15.80S 14 48 0 49 31 13 5 47 49 -9 46 217 0.97 217.0 197.29 15.81S 14 51 0 49 28 22 5 47 58 -9 46 217 0.97 217.0 197.30 15.82S 14 54 0 49 25 30 5 48 7 -9 46 218 0.97 217.0 197.30 15.83S 14 57 0 49 22 38 5 48 15 -9 46 218 0.97 217.0 197.31 15.84S 15 0 0 49 19 46 5 48 24 -9 46 218 0.97 217.0 197.32 15.85S 15 3 0 49 16 53 5 48 33 -9 46 218 0.97 217.0 197.33 15.86S 15 6 0 49 14 1 5 48 42 -9 46 218 0.97 217.0 197.34 15.87S 15 9 0 49 11 8 5 48 50 -8 46 218 0.97 217.0 197.35 15.88S 15 12 0 49 8 14 5 48 59 -8 46 218 0.97 217.0 197.36 15.88S 15 15 0 49 5 21 5 49 8 -8 46 219 0.97 217.0 197.37 15.89S 15 18 0 49 2 27 5 49 17 -8 46 219 0.97 217.1 197.38 15.90S 15 21 0 48 59 34 5 49 25 -8 46 219 0.97 217.1 197.39 15.91S 15 24 0 48 56 39 5 49 34 -8 46 219 0.97 217.1 197.39 15.92S 15 27 0 48 53 45 5 49 43 -8 46 219 0.97 217.1 197.40 15.93S 15 30 0 48 50 51 5 49 52 -8 46 219 0.97 217.1 197.41 15.94S Path coordinates are referred to WGS84 (as used by GPS). Librations Long +3.88 Lat -1.25 P +197.4 D -2.1 Illumination of moon 63%- Elongation of Moon 105 Vertical Profile Scale 2.57 km/arcsec at mean distance of moon Horizontal Scale Factor 1.49 deg/min
Affected moon limb with measurement points P,D(+/-0.5 deg) from previous observations (zero-line for 530m WGS84)
The selected observation position relativ to the path for 530m was on + 1000 meters Satellite view of grazing path in northern woodquarter
Observation report
Date Observer Position Observer 2006/12/11 48° 53´ 00.28" North (WGS84) Gerhard Dangl Star 15° 26´ 48.11" East (WGS84) 3830, Nonndorf 12 ZC 1522 = SAO 99098 486.4m (MSL), 530.7m (WGS84) AUSTRIA
TELESCOPE: Type: Newton Focal length: 1200mm Aperture: 254 mm Magnification: video/primary focus/recorded field 1112" x 830" Mount: Equatorial EQ6 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: good Wind: No Star image stability: fair Temperature: 270 Kelvin (-03 deg Celsius) ADDITIONAL COMMENTS: Predictions with Occult3.6 A total of 12 graze events (6D/6R) on the dark limb of the moon recorded Video evaluation accomblished with VirtualDub1.6.16 and Limovie0.9.24 Another verification with brand new Limovie0.9.25 did not change results Due to seeing effects no diffraction was verifiable 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 44.3m
A total view of the grazing occultation with 12 events - Click on a number shows detail graph
Table with observed events and results of video measurement
Nr. Date Comment Video time UT SAO Mag hh:mm:ss.sss +/- s
1 2006/12/11 Disappearance level 50% 05:47:06.507 0.010 99098 6.8 1 2006/12/11 Disappearance level 0% 05:47:06.647 0.010 99098 6.8 Star occulted for duration 00:00:36.459 0.020 99098 6.8 2 2006/12/11 Partial reappearance start 05:47:42.886 0.010 99098 6.8 2 2006/12/11 Partial reappearance relative level 50% 05:47:42.966 0.010 99098 6.8 Star partial visible for duration 00:00:00.080 0.020 99098 6.8 3 2006/12/11 Disappearance relative partial level 50% 05:47:43.046 0.010 99098 6.8 3 2006/12/11 Disappearance level 0% 05:47:43.106 0.010 99098 6.8 Star occulted for duration 00:00:06.920 0.020 99098 6.8 4 2006/12/11 Reappearance start 05:47:49.826 0.010 99098 6.8 4 2006/12/11 Reappearance level 50% 05:47:49.966 0.010 99098 6.8 Star visible for duration 00:01:15.118 0.020 99098 6.8 5 2006/12/11 Disappearance level 50% 05:49:05.084 0.010 99098 6.8 5 2006/12/11 Disappearance level 0% 05:49:05.344 0.010 99098 6.8 Star occulted for duration 00:00:00.580 0.020 99098 6.8 6 2006/12/11 Reappearance start 05:49:05.384 0.010 99098 6.8 6 2006/12/11 Reappearance level 50% 05:49:05.664 0.010 99098 6.8 Star visible for duration 00:00:00.500 0.020 99098 6.8 7 2006/12/11 Disappearance level 50% 05:49:06.164 0.010 99098 6.8 7 2006/12/11 Disappearance level 0% 05:49:06.464 0.010 99098 6.8 Star occulted for duration 00:00:21.560 0.020 99098 6.8 8 2006/12/11 Reappearance start 05:49:27.644 0.010 99098 6.8 8 2006/12/11 Reappearance level 50% 05:49:27.724 0.010 99098 6.8 Star visible for duration 00:00:05.980 0.020 99098 6.8 9 2006/12/11 Disappearance level 50% 05:49:33.704 0.010 99098 6.8 9 2006/12/11 Disappearance level 0% 05:49:33.824 0.010 99098 6.8 Star occulted for duration 00:00:05.699 0.020 99098 6.8 10 2006/12/11 Reappearance start 05:49:39.303 0.010 99098 6.8 10 2006/12/11 Reappearance level 50% 05:49:39.403 0.010 99098 6.8 Star visible for duration 00:00:39.520 0.020 99098 6.8 11 2006/12/11 Disappearance level 50% 05:50:18.863 0.010 99098 6.8 11 2006/12/11 Disappearance level 0% 05:50:18.923 0.010 99098 6.8 Star occulted for duration 00:00:20.539 0.020 99098 6.8 12 2006/12/11 Reappearance start 05:50:39.342 0.010 99098 6.8 12 2006/12/11 Reappearance level 50% 05:49:39.402 0.010 99098 6.8
PLACE NAME Obergruenbach
ADDRESS A-3822, Austria
E-MAIL ADDRESS gerhard@dangl.at
REPRESENTATIVE Gerhard Dangl
REPORTED TO ILOC
TA NED 25.4 120.0 15 26 48.1 E 48 53 00.3 N 530.7GPS (WGS84)
OA Gerhard Dangl
012006121105470651 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
022006121105474297 S 99098 2V MS 0011 212-3 6 AAA
Partial (50%) reappearance; VTI with KIWI-OSD+GPS
032006121105474305 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
042006121105474997 S 99098 2V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
052006121105490508 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
062006121105490566 S 99098 2V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
072006121105490616 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
082006121105492772 S 99098 2V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
092006121105493370 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
102006121105493940 S 99098 2V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
112006121105501886 S 99098 1V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
122006121105503940 S 99098 2V MS 0011 212-3 6 AAA
Video time insertion with KIWI-OSD and GPS
INTERNATIONAL LUNAR OCCULTATION CENTER (ILOC) PRELIMINARY REDUCTION OF LUNAR OCCULTATION OBSERVATIONS FOR REPORT R1438
TEL CODE 1 LOCATION(E 15 26 48.10 N48 53 0.30 530.7M (DM 84 WGS84 ) TELESCOPE(AP 25CM FL 120CM TYPE NED)
OBS CODE 1 Gerhard Dangl
DATE TIME(UTC) AGE CT STAR NO. MAG PH TEL OBS REC O-C(")HW(") K-R(DEG)KM(DEG) H92 SOURCE SAO DM REPORT DAT.NO.
6 12 11 5 47 6.51 20.3 S 99098 6.8 DD 1 1 1 0.02 2.27 96.9 213.2 H 15584 P 50950 99098 +11 2217 143800 0001
6 12 11 5 47 42.97 20.3 S 99098 6.8 RD 1 1 1 -0.60 2.02 97.8 214.1 H 15584 P 50950 99098 +11 2217 143800 0002
6 12 11 5 47 43.05 20.3 S 99098 6.8 DD 1 1 1 -0.60 2.02 97.8 214.1 H 15584 P 50950 99098 +11 2217 143800 0003
6 12 11 5 47 49.97 20.3 S 99098 6.8 RD 1 1 1 9.99 -9.99 98.0 214.2 H 15584 P 50950 99098 +11 2217 143800 0004
6 12 11 5 49 5.08 20.3 S 99098 6.8 DD 1 1 1 0.52 -0.23 99.8 216.1 H 15584 P 50950 99098 +11 2217 143800 0005
6 12 11 5 49 5.66 20.3 S 99098 6.8 RD 1 1 1 0.49 -0.21 99.8 216.1 H 15584 P 50950 99098 +11 2217 143800 0006
6 12 11 5 49 6.16 20.3 S 99098 6.8 DD 1 1 1 0.48 -0.20 99.8 216.1 H 15584 P 50950 99098 +11 2217 143800 0007
6 12 11 5 49 27.72 20.3 S 99098 6.8 RD 1 1 1 -0.30 0.47 100.4 216.7 H 15584 P 50950 99098 +11 2217 143800 0008
6 12 11 5 49 33.70 20.3 S 99098 6.8 DD 1 1 1 -0.13 0.29 100.5 216.8 H 15584 P 50950 99098 +11 2217 143800 0009
6 12 11 5 49 39.40 20.3 S 99098 6.8 RD 1 1 1 -0.01 0.16 100.7 217.0 H 15584 P 50950 99098 +11 2217 143800 0010
6 12 11 5 50 18.86 20.3 S 99098 6.8 DD 1 1 1 0.59 -0.35 101.7 217.9 H 15584 P 50950 99098 +11 2217 143800 0011
6 12 11 5 50 39.40 20.3 S 99098 6.8 RD 1 1 1 -0.09 0.49 102.2 218.4 H 15584 P 50950 99098 +11 2217 143800 0012
27 January 2007 |
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