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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. Topics. June was a very good month for firsts Observed an occultation by (II) Deimos Observed an occultation by (28978) Ixion
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Recent Occultations by Deimos and Ixion William H. Hanna Alice Springs, NT Australia IOTA 32nd Annual Meeting 13 July 2014 College Park, MD USA
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
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.
Short video of the Deimos occultation (note that Mars is greatly overexposed) <insert/play Deimos video here>
Ixion prediction Credits: Rio Team & B. Sicardy
The target star was a double Credit: Jose-Luis Ortiz
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
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