Recent Occultations by Deimos and Ixion William H. Hanna Alice
Springs, NT Australia IOTA 32 nd Annual Meeting 13 July 2014
College Park, MD USA
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Topics June was a very good month for firsts Observed an
occultation by (II) Deimos Observed an occultation by (28978) Ixion
Current setup Historical results
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The Deimos prediction came just in time I normally use Occult
Watcher for long-term planning, but John Broughton, a prolific
occultation observer based in Queensland, was examining upcoming
predictions made by Occult 4 and found that a narrow (~12 km)
predicted path for (II) Deimos, not currently listed in an OW feed,
would pass just to the south of Alice Springs. John sent me an
e-mail (giving barely four hours notice) and I immediately set up
under ideal observing conditions. Observed a 1.5-second (of a
possible 1.8-sec) occultation. The accuracy of the prediction was
no doubt due in large part to the fact that the target star was in
the Hipparcos catalog.
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The Deimos Prediction
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The result (at 30 fps)
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Short video of the Deimos occultation (note that Mars is
greatly overexposed)
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Ixion prediction Credits: Rio Team & B. Sicardy
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Dim target star
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Gone
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The result (at 3 sec. per frame)
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The target star was a double Credit: Jose-Luis Ortiz
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Post-observation updated prediction
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My current setup 8 Meade LX90 f/10 with a Meade f/3.3 focal
reducer at prime focus; polar mount Occasionally use a 14 Meade
LX-200 GPS Point Grey Research Grasshopper EX GX-FW-28S5M Sony
ICX674 2/3 1920x1440 14-bit CCD Astronomical Digital Video System
(I am a beta tester) ADV Recorder v1.5.71 under Ubuntu Linux 12.04
LTS Fujitsu Lifebook E752 Laptop (Linux / Windows 7) with an IEEE
1394b 800 Mbps FireWire ExpressCard
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Recent observations are from my balcony
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on a pier relocated from the hillside
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Results of 135 attempts (as of 20140628) Observed an
occultation: 11 Observed a miss: 76 No observation: 48 Weather: 33
Equipment problems: 4 Self-induced: 11 Target star too dim for my
equipment: 4 Not set up in time: 3 Misidentified star field: 1
Software feature: 1 Personal reasons: 2
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Positives (52)Europa20120704 (I)Charon20120727 (using a 14)
(134340)Pluto20120826 (using a 14) (92)Undina20130206
(790)Pretoria20130320 (578)Happelia20130506 (372)Palma20140217
(65)Cybele20140422 (II)Deimos20140617 (28978)Ixion20140624
(198)Ampella20140625