Lunar%20Occultations%20of%20Close%20Double%20Stars

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LunarOccultations of Close Double Stars
Occultation of R946, 2011 November 14
The why and wherefore of observing these events
NACAA 2014 April 20 Occultations
Session Brian Loader RASNZ Occultation Section
SAO 160149 2013 September 12
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SAO 160149 Occultation Video Frame
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Occultation Light Curve, Single Star
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Occultation Light Curve for SAO 160149
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Double Star Occultation, Light Curve
Secondary Intensity
Step Length (seconds)
Primary Intensity
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Double Star Occultation, Light Curve
176 78
Step Length (seconds)
367 42
1.16 s
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Double Fainter Star second
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Double Reappearance
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Double Star Programme Aims
md
Accurate times of both events
Position Angle and Separation
and Magnitudes
Discovery of new doubles
Confirmation / Rejection
Publication of results
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Solution for R68 using OCCULT
N
E
E
Prediction 0.092 258.37
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Possible Resolution
2 or 3 video frames, ca 0.1 second
ca 30 to 35 milli arc-second...

60 m on the moon,
1AU at 100 light years.
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Total Number of Observations Archived as at 2014
April 6
Year of Obsn. No of Obsn Cumulative
up to end 2007 147 147
2008 75 222
2009 223 445
2010 249 694
2011 196 890
2012 222 1112
2013 184 1296
2014 65 1361
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Numbers of Observations Receivedas at 2014 April
6
Group No. of Obsn. No. of stars No. gt 1 Obsn. Max obsns. per star
WDS double 393 209 87 7(2 nil)
WDS single 148 96 34 4
OCc double 35 19 8 3
OCc single 498 310 125 6
Discoveries 109 82 14 6(2 nil)
Doubtful Dbl 98 75 15 4
Wide Dbl gt3 80 64 11 5
TOTALS 1331 855 294
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Numbers of Observers by Country
Australia 11 New Zealand 4 Japan 17 USA
9 Europe 7
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Publication
Suitable observations are published in the
on-line Journal of Double Stars
Observations. http//www.jdso.org
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Discovery Papers
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JDSO July 2010
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JDSO July 2011
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JDSO October 2012
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JDSO April 2014
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Known doubles, PA and Separation Measured
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Occultation Discoveries
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Possible Double Stars shown to be single
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Observer Separation
10 round the Moons limb projected on the
Earths surface is ca 3 latitude
Hobart Melbourne ca 5
Melbourne Sydney ca 4.5
Sydney Brisbane ca 6
Brisbane Rockhampton ca 4.2
Perth Adelaide Murrumbateman
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