Recent successful asteroidal occultations in our region in the past year. Paper to be presented to NACAA 2014/ TTSO8 April 2014 John Talbot (NZ) RASNZ Occultation Section

Abstract A selection of interesting minor planet occultation results observed from Australia and New Zealand during 2013 is presented. More details are available in the PDF file that has been submitted.

Some Statistics Since 2006 the number of events with positive observations for the region has run: 2006 – 23, 2007 – 31, 2008 – 47, 2009 – 46, 2010 – 50, , 2012 – 51, The number of individual reports increased from last year: Our total number of observers rose by about 32% and positive events by 15%, and the number of reports has increased by about 39%, compared to last year. Our top observers (positive and negatives) were Brian Loader with 80, John Broughton with 54, Chris Chad 37, Jonathan Bradshaw with 26, and Bill Hanna and Dave Herald with 22 each The Occsec web site now has over 750Mb of disk space used, most for predictions and results, and is growing at over 50 Mb per year. During the year we had to change our web host service and our URL which is now YearReportsObserversPositive observationsNegative observations

Positive Results 6 chords: 2013 July 26 08:54 (576) Emanuela occultation - (6 chords 4 Misses) Observers: 1(M) D Watson, Thornton near Whakatane, NZ 2(M) P Anderson, THE GAP, Brisbane,QLD,AU 3(M) T.Napier-Munn,Brisbane, QLD,AU 4 S Mudge,Willowbank,QLD,AU 5 J Broughton,Reedy Creek, QLD, AU 6 J Broughton,Clothiers Creek, NSW, AU 7 S Broderick,Toowoomba, QLD,AU 8 J Broughton,Brunswick Heads, NSW, AU 9 J Broughton,Bangalow, NSW, AU 10(M) J Talbot,Waikanae Beach, NZ 11(M) M Forbes,Lower Hutt 12(P) Prediction, 04 July

Positive and double star Observers: 1(M) D Watson,Thornton near Whakatane, NZ 2 W Hanna,Alice Springs, NT,Australia 3 J Broughton,Pimpama, QLD, AU 4 J Broughton,Pimpama, QLD, AU 5 J Bradshaw,Samford Valley, Qld, AU 6 J Bradshaw,Samford Valley, Qld, AU 7 J Broughton,Reedy Creek, QLD, AU 8 J Broughton,Reedy Creek, QLD, AU 9(P) Prediction, 27 January Paper in JDSO Vol. 9 No. 4 October 1, 2013 P FEBRUARY 06 OCCULTATION OF TYC BY 92 UNDINA

Positive Results 4 chords: 2013 May 12 (654) - Zelinda occultation - (4 Chords) Observers: 1 J Talbot,Waikanae Beach, NZ 2 P Graham,Martinborough,NZ 3 B Allen,Blenheim, NZ 4 G McKay,Blenheim, New Zealand 5(P) Prediction

Best Positive Results 4 chords and DAMIT model: 2013 October 25 - (8) Flora occultation - (4 Chords) Observers: 1 G Hudson, Porirua, NZ (Cloud ) 2 B Allen, Blenheim, NZ 3 G Blow etal, Carter Obs Wellington, NZ 4 L Field,Kaikoura,NZ 5 B Loader,Darfield,NZ 6(M) A Pennell,B Begg Observatory Dunedin NZ 7(P) Prediction, 15 Sept This was the preferred DAMIT model and shows good fit

TYC Double star 2013 August 15 - (481) Emita occultation - (New double star discovery) ObserverTelescopeCameraTimingEvent S. Kerr, QLD,AU30 cmWatec 120N+ videoGPS Time InsertedStepped D and R

4 Possible solutions for PA and separation. Might have been resolved if another observation. Published in JDSO Vol. 10 No. 2 April 1, 2014 TYC Double star 2013 August 15 - (481) Emita occultation - (New double star discovery)

2013 August 15 - (611) Valeria occultation - (New double star discovery) UCAC Double star ObserversTelescopeCameraTimingEvent C. Chad, NSW,AU25 cmSamsung SCB-2000 Video GPS time inserted2 separate dips J Broughton, QLD,AU25 cmWatec 120N+ videoGPS Time InsertedMiss P. Anderson, QLD,AU41 cmVisualRadio TimeMiss Different level for the dips implies a double star with different magnitudes rather than two similar sized rocks

2013 August 15 - (611) Valeria occultation - (New double star discovery) Two of 4 possible solutions shown above Again may have been resolved with another chord Published in JDSO Vol. 10 No. 1 January 1, 2014 UCAC Double star

Was this the first indication of rings around Chariklo? Recent paper by Felipe Braga-Rigas in Nature annuoncing rings discovered using occultations observed in South America July 03 Occultation of UCAC2_ by Chariklo Observers: Barry & Horvat-LightCurve The problem is the yellow comparison star trace shows similar blips so more likely to be atmospheric scintillations. But….

Conclusion Minor planet occultation observing continues to be alive, well and still growing in Australasia. We have shown in the past that for some events we can muster 20 or more stations But we could always do with a few more reports and a few more regular observers, for the less exciting and smaller object events, Particularly in the North of the North Island, NZ and N, S and W of AUS.

Issues ? Always remember that a result with more than one chord measured is MUCH more valuable than those with only one. Error for 1 chord = +/- 1 Radius. Error for one chord on each side of object about +/-0.1 Radius Check in OW and join a team event! Remember that it may take you a while to find your target so start setting up early, or better still find your target the previous night at about the predicted time. You become familiar with asterisms you may use for prepoint or star hopping. I find that my first attempt to find a prepoint target takes me anywhere between 20 mins and an hour but the next night I can usually get there in under 20 mins. In particular I find it useful to note the RA and Dec setting circle readings on my mount on the test night so that I can get back there and already be close to the track.

Thanks to: Dave Herald for Occult and new work on IOTA Hristo for Tangra and new work on IOTA Kazuhisa Miyashita for Limovie Bob Anderson and Tony George for Occular Kiwi-Jeff for Kiwi-OSD Dave G and his team for the IOTA-VTI and ADVS Josef Durech from Prague, Czech Republic, for providing DAMIT 3D model service Przemysław Bartczak from Poznan, Poland for providing the ISAM 3D model service NASA and US Navy for GPS, TYC, UCACx, NOMAD, … The makers of Telescopes, Videocams, VCRs, DVRs, PCs, … Without out these tools we would not be able to produce these results. And of course all the observers who stayed up to observe and send in 532 reports.

Special Thanks to: Murray Forbes Editor of The Occsec Circular I wish to give a special thank you to Murray Forbes who has been working on catching up on the backlog of all observations reported in our region in a Journal format. The events have now been completed. I hope he can further close the gap this year. AND I would also like to thank Dave Gault for his work in putting together the program for TTS08 this year.

Finally a special mention for Graham Blow Director of RASNZ Occsec, who was recently made an Officer of the New Zealand Order of Merit in the New Year's Honours List for service to Astronomy. Thanks Graham for being my mentor for the last 8 years

The End – Questions ? My 10 inch occultoscope on 1960s C Frank, UK, mount. Big improvement on the BBQ motor drive I previously used And now equipped with WATEC 120N+ thanks to Dave G.