The International Occultation Timing Association's  31st Annual Meeting

David Dunlap Observatory, Richmond Hill, Ontario, Canada

October 4-6, 2013

by Richard Nugent, Executive Secretary

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Scotty’s Maxi mount to hold a 120mm short tube refractor

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Lifetime Achievement Award to David W. Dunham

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Homer F. Daboll Award to Graham L. Blow

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David E. Laird Award to Harold R. Povenmire

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Paul Maley setup for 41 Daphne occultation in Indonesia

 

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Group Photo

 

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David Dunlap Observatory

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IOTA at NEAF conference

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David Dunham given IOTA's Lifetime Achievement Award

 

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Io's torus and light curve 

 

The minutes of all IOTA annual meetings are at:

http://www.poyntsource.com/Richard/IOTA_Annual_Meetings.htm

 

Graham L. Blow, 2013 Homer F. Daboll Award Recipient (photo coming soon)

Harold R. Povenmire, 2013 David E. Laird Award Recipient 

David W. Dunham, Lifetime Achievement Award Recipient

The 31st annual meeting of the International Occultation Timing Association was held  Friday, Saturday and Sunday October 4-6, 2013 at the David Dunlap Observatory at Richmond Hill, Toronto, Ontario, Canada . This location coincided with the occultation of the asteroid 307 Nike covering a 118-km wide projected path west and north of Toronto on the evening of October 6, 2013. (at event time, this Nike event was canceled due to cloud cover).

The meeting location was kindly hosted by the David Dunlap Observatory. The final meeting schedule, and most of the presentation files, are located as links from Brad Timerson’s North American Observations web site:  

http://www.asteroidoccultation.com/observations/NA/2013Meeting/2013Presentations.htm

Forty-eight (48) persons participating in the meeting in person and via internet conference:

On site attendees: President Dr. David Dunham from Maryland, Vice President Paul Maley from Texas, President elect Steve Preston from Washington State, Dr. Joan Dunham from Maryland, , Hal/Katie Povenmire, Dr. Terry Redding from Florida, Ralph Chou, Guy Nason, Paul Mortfield, Michelle Johns, Tom Luton, Denis Grey, Diane Shukla from Toronto, Frank Dempsey, Ron Macnaughton from Ontario, April/Shannon Russell, Eric Briggs, Brenda Shaw from New York.      

Video Internet Conference  Attendees:  Steve Messner, Brad Timerson, Ted Blank, Steve Conard, IOTA Treasurer Chad Ellington,  IOTA Executive Secretary Richard Nugent, Bob Anderson, Tony George, Bob Dunford, Ted Swift, Derek Breit, Roger Venable, Bruce Holenstein, Ernie Iverson,  Jan Manek, Bob Sandy, Brian Loader, Dave Gault, Dave Herald, Graham Blow, Hristo Pavlov, John Broughton, Marjan Zakerin, Rob Robinson, Jacquie Milner, Scott Degenhardt, Wayne Warren, Breno Giacchini

12:00PM – Meeting start – Introductions

President Dr. David Dunham opened the meeting and welcomed everyone  to the David Dunlap observatory which was built in 1934.  He then asked the attendees to introduce themselves. All present at the Observatory introduced themselves.

Business meeting:

Treasurer Chad Ellington presented IOTA’s membership status. Currently there are 43 USA print subscribers plus 5 outside USA , (vs. 67 in 2012) 46 online subscribers (vs.20 in 2012. This is a net decrease of 38 members from last year.

Expense report: A summary of the year’s bank balances are:

Starting Balance:                   $5,997.29     2012, Oct 19

Ending Balance:                    $6,038.02     2013, Oct3

     Net Inecrease in Balance:      $   40.73

The breakdown of this past year’s budget is:

          Membership Income:       $960

          Interest:                           $4.53

          IOTA-VTI Royalties:      $381

          PayPal Balance:               $1060.00

          Expenses:

                   -Printing/Mailing    $1,301.32

                   -JOA:                    $790.67

                   -Web Service:        Still Donated

                   -Awards:               $ Not determined

                   -Fees:                    $44.97 (paypal)

                    -Change

                     of registered agent $5

Chad mentioned that except for the current issue the Journal of Occultation Astronomy (JOA) it is within one month of being on schedule. Online subscribers will see the JOA issues uploaded well before the print issues are delivered. 

Executive Secretary Richard Nugent presented election results as 2013 is an election year. After 30 years as President and Vice President David Dunham and Paul Maley decided to step down and let new blood run the organization. Dunham and Maley are not leaving IOTA, they will remain on its Board of Directors. Expect to hear from them with their observations, wide range of expertise and input as before. Jan Manek retired after 15 years as VP for Planetary Occultations. Jan’s volunteer work for IOTA has been held in the highest regard by the occultation community.

The new slate of candidates that were voted on were:

   President: Steve Preston
   Vice President: Roger Venable
   Executive Secretary: Richard Nugent
   Secretary & Treasurer: Chad Ellington
   V.P. for Grazing Occultation Services: Mitsuru Soma
   V.P. for Planetary Occultation Services: Brad Timerson
   V.P. for Lunar Occultation Services: Walt "Rob" Robinson

A total of 29 votes were received by email, none were received by Post Office mail. No nominations were received and Richard certified the election, and the candidates were officially installed into their respective positions.   

Newly elected Vice President for Planetary Occultations Brad Timerson gave the status of publications. He listed some articles from the Minor Planet Bulletin from 2009-present, and one article in press submitted to Planetary and Space Science Journal regarding Steve Conard’s discovery of a possible satellite of 911 Agamemnon from a video he made. Joan Dunham’s  had nominated  the name “Kephalos” as a name for the Agamemnon satellite.   

He showed the binary asteroid 90 Antiope occultation profile from July 2011 which an article is currently pending. He asked for help in someone to write these papers and showed a list of asteroid events since Jan 2011 that are candidates for future articles. Paul Maley said in order to maintain IOTA’s credibility and status we need to keep publishing these articles.

Paul Maley showed Steve Conard’s presentation on insurance and liability for IOTA activities. The major question is: does IOTA need liability insurance? IOTA has no property and virtually no assets. Several types of insurance options were shown to protect people on IOTA expeditions.  They are General Liability and Director and Officers (D&O) Liability. Even without liability, this won’t prevent a lawsuit. The D&O coverage would pay for legal expenses. 

IOTA has been doing expeditions since 1975 and formerly incorporated in 1983. Paul got a quote from State Farm (quote for Texas only) this past summer. Premiums ranged from $1,066 to $1,403 per year. IOTA has never had a legal issue or lawsuit thus this issue needs further discussions by the Officers before a decision is made.

Hal Povenmire mentioned an upcoming bright star occultation of ZC 2629  and ZC 2826 as these are suspected binary stars. These occultations are visible from the eastern USA . He called for video observations of this event to confirm/deny their binary status.

(10 minute break)

Ted Blank (for Walt Morgan) presented the IOTA-VTI Status Report. IOTA has the rights to the IOTA-video time inserter. It’s manufactured by Video Timers and technical details are handled by Walt Morgan and Sandy Bumgarner. The basic unit has a built in GPS receiver and an external GPS is available. Sale prices have not changed since its introduction 2 years ago, $249 for the basic unit, $300 with an external GPS and $350 for both internal and external GPS. Total sales thus far since 2011 – about 160 have been sold. Royalties paid to IOTA have exceeded $200-$300 for each half-year.

Tony George presented the double star report. Four papers were published in the Journal of Double Star Observations (JDSO) since October 2012 showing new double stars discovered. New double star discoveries are:

3UC197-115376   by  asteroid 336 Lacadiera, event date 2009 April 6

BN Orionis, (TYC 126-0781-1)  by asteroid 57 Mnemosyne, event date 2012 March 11

TYC 6223-00442-1 by  asteroid  52 Europa, event date 2012 August 12

UCAC2 42913552 by asteroid 388 Charybdis, event date 2012 December 3.

Tony next discussed R-OTE, the Occultation Timing Extractor. R-OTE is a signal analysis tool that he and Bob Anderson have developed. It’s a more advanced estimator than OCCULAR to extract D and R occultation timings. A major difference from OCCULAR is that R-OTE independently determines D and R events, whereas with OCCULAR they were linked by the duration of the event. Other advances are the ability to estimate stellar diameters and occultation limb angles, limb darkening models, and extract difficult to see events from low SNR light curves with high confidence.  He showed some light curves and how R-OTE used the maximum likelihood estimator (MLE) and Akaike Information Criterion (AIC) for light curve fit and model selection.  Examples were also shown on how R-OTE uses advanced methods to deal with noise and SNR issues.

Paul Maley asked if R-OTE could be used to reexamine previous videos made at the limits of the occultation where no event was initially seen in the hope of extracting a real event. Tony responded yes and that it would be limited by the amount of noise in the data.

Tony’s next talk was about Near Earth Asteroids (NEA’a) and IOTA’s possible future involvement. New proposed research (not yet funded) by the Cascade Airless body Research Institute (CARI) is to characterize the properties of observed NEA’s including IR measurements, thermophysical properties, effects of space weathering, sample return technology and physical measurements using occultations/light curve data. Equipment currently available for this project is Columbia Basin ’s  Moore observatory telescope, Pacific Northwest Regional Observatory (PNRO) and some high speed CCD cameras with frame rates on the order of 1,000’s of frames/sec. If the project is funded, Tony would be a principle investigator in charge of the occultation method for determining the physical properties of NEA’s. The grant award will be decided upon in November 2013.

Paul Maley discussed the status of funding from the Southwest Research Institute (SwRI) for asteroid occultation events. Thus far 387 Aquitania (July 26, 2013) was the first and only event funded  from this past summer 2013. The process for picking and determining events to be funded is on the IOTA 2012 and 2013 annual meeting presentation pages along with how observers would get reimbursed for expenses. Paul showed  SwRI’s target events for 2014 and path maps. Paul mentioned that in order to continue to have chances at funding, IOTA must publish results in journals and on its web pages and have a plan to attract outside donors.      

David Dunham  presented how to observe asteroid occultations from multiple stations. This same talk was presented at the European Symposium on Occultation Projects (ESOP-32) in Barcelona , Spain on August 25, 2013. This is a technique he first devised for a September 2001 asteroid event in Orland , California and the method has been expanded and polished over the past 12 years by a host of experts: Roger Venable, Scotty Degenhardt and Paul Maley.

Meeting attendees then discussed plans for the 306 Nike event Saturday night with a +10.6 magnitude star and went to dinner.

The meeting adjourned at 5:35 PM EDT.

Saturday October 6, 9:10 AM meeting continues

Hristo Pavlov discussed OccuRec – A new video Recording software for windows. A main issue with windows recording of occultations is the delay in getting the time stamps in synch with the video. Hristo came up with a program that solves these issues. He demonstrated how to run this program with on his desktop for all to see. Terry Redding asked which captre cards will work with the software and Hristo said all capture cards that work with direct Show will work.

He next talked about the new Watec camera WAT 910-BD. It will have a sensor that is 2 times more powerful than the WAT-910HX camera. He acquired a WAT 910-BD camera and did some tests compared to WAT 120N, the WAT 910 HX. Many more stars were visible.

 Bruce Holenstein  presented a talk entitled on “Application of EMCCDs to Faint Occultations”. A “faint” occultation is considered one that is out of the reach of typical IOTA equipment, where the target star is in the range of magnitude +14 or fainter. A “emCCD” is a camera with an extra set of registers to multiply electrons before readout. Bruce showed slides on how emCCDs work and their noise characteristics and how noise is significantly reduced. These emCCD cameras are much larger than our conventional video cameras and Bruce showed some photos of how he mounts them on his telescope.  In tests on a 14” f/10 SCT, he observed stars to m = +17 with a Photometrics 512B emCCD camera.

The camera had much improved signal to noise (SNR) over the Stellacam EX camera and reached stars 2 or 3 magnitudes fainter.

 

The emCCD cameras are capable of very fast recording rates. An example occultation of mu GEM from March 2013 was shown with a phenomenal 333 frame/sec recording rate.  The light curve graph clearly showed effects of the large 16 mas angular size of the star.  

 

10 minute break, resumed 10:35 AM EDT

Dr. Marjan Zakerin of IOTA-ME presented the Scientific Achievements of IOTA-Middle East Section and some of their recent activities. IOTA-ME was formed just 3 years ago in  2010. IOTA_ME has two departments: Occultations/ TNO’s (12 members) and Variable stars/Exoplanets (50 members).  She showed slides on several projects they are currently working on. IOTA-ME has published 34 monthly newsletters since their creation. The newsletters have articles presenting original research by its members. They are currently translating a book on exoplanets for use by its members and writing a book on analysis of light curves from IOTA-ME experiences/observations. IOTA-ME has participated in several workshops concentrating on hands on training for its members – how to make observations, writing papers, analyzing results, etc. They participated in the 3rd international Conference of Occultation and Eclipses in October 2012 and will participate in the 4th conference scheduled starting October 24, 2013. With 62 members, they are one of the largest IOTA organizations in the world.

 This year’s presentation of the annual Homer F. DaBoll award and David E. Laird award was made by the Award Committee Chair Dr. Terry Redding. The Homer F. DaBoll award is given annually to an individual in recognition of significant contributions to Occultation Science. “Occultation Science” is limited to actual IOTA research: total and grazing occultations, asteroid occultations and solar eclipses. The David E. Laird award (this being the first award year) is given to people who have made significant contributions to occultation science prior to 15 years ago. Laird (1931-1968) was an organizer of grazing occultations in the early 1960’s. The Laird award was conceived to help “catch up” on awards to some older IOTA members.

Previous Homer F. Daboll awardees: 2007: Dave Herald ( Australia ), 2008: Edwin Goffin (Europe), 2009: Steve Preston (USA), 2010: Hristo Pavlov ( Australia ), 2011: Scotty Degenhardt (USA), 2012: Kazuhisa Miyashita ( Japan ).

This year’s Award Committee consisted of all past recipients (above) and Dr. Terry Redding ( Florida - chairman).  This year 15 nominations were received – 6 for the Daboll award and 9 for the Laird award. The Committee’s main objective in selecting an award recipient was to reach a consensus and not choosing someone by a majority vote. Eligibility for the award is for anyone who has made significant contribution to occultation science or for the work of IOTA and its goals. Persons not eligible are current IOTA Officers & the award committee. Candidates nominated are not required to have IOTA membership.   

The 2013 Homer F. DaBoll award recipient was Graham L. Blow from New Zealand for his dedicated leadership, the establishment of TTSO and the editorship and promotion associated with occultations, grazes and eclipses. Graham was online and made and graciously accepted the award. Graham has been President of the Royal Astronomical Society of New Zealand for 20 years.

The 2013 David  E. Laird went to Harold. R. Povenmire of Florida for his 50 years of  grazing occultation work including leading expeditions, authoring, teaching, training and observing.  Hal was present at the meeting and told a few funny stories about some of the early days of occultations.  Hal’s achievements include: being one of the first grazing occultation observers on Oct 8, 1963, leading over 500 expeditions, may have been the first person to see an asteroid moon – 129 Antigone, on Oct 12, 1974, he worked with Paul Maley to help obtain 235 chords of the Pallas occultation in 1983, published the firstt book of grazes in 1977 and co-authored the Occultation Observers Handbook in 2006, published over 250 articles on occultations and other solar system fields (meteorites, Tektites, space science) and  Hal is the only person that has two asteroids named after him  - 12753 Povenmire and 15146 HalPov !

Terry then presented a Lifetime Achievement Award  to David W. Dunham. The award inscription reads, “For His Leadership, Commitment And Tireless Efforts Toward The Promotion Of  All Aspects Of Occultation Science. IOTA Looks Forward To His Ongoing Contributions”.  David Dunham is the father of the modern occultation program having started his interest  when he was 15  years old in 1957 and making numerous milestones since then. A YouTube video of this award presentation is here:

http://www.youtube.com/watch?v=3ru6Fq9pijw 

 Lunch Break, resumed 1:30PM EDT

Ted Blank presented a summary of IOTA’s participation in the North East Astronomy forum (NEAF). Joining Ted at that event was Dr. Ken Coles, Steve Conard, Bruce Holenstein, Bruce Berger and Al Carcich. Over 4,000 people attended this event which lasted 2 days. IOTA offered a class both days, “Introduction to Occultations”. For NEAF attendees Walt Morgan offered a $15 discount on the IOTA-VTI time inserter. A sign up sheet had 33 people sign up and a few of these people are in contact with current IOTA members. Brochures were passed out, the IOTA-VTI was displayed the ten-inch travel scope was set up and shown and sample graze profiles and asteroid profiles were displayed. The cost of IOTA attending was $450 of which IOTA paid $300 and the balance came from other members/companies. Feedback from NEAF included Elizabeth Warner’s offer to consolidate all of IOTA‘s myriad of websites into a single front-end website.

Steve Conard updated the results of the Astronomical League’s Occultation Program status. Three years in the making, the Astronomical League (AL) finally accepted IOTA’s occultation observing program at their 2013 meeting. Initially the AL rejected the observing program in 2012 and asked IOTA to re-submit. Ted Blank presented the program at the AL 2013 meeting in Atlanta and it was accepted. The occultation program is on the AL website and right away 4 people inquired about and plan to try the program. Steve then showed a slide listing the requirements to get the occultation observing pin.

Paul Maley presented the results of the 196 Philomela and 41 Daphne international occultation events earlier in 2013 as part of his outreach efforts to foster interest in these events. Both these paths had bright stars good path statistics. Paul observed the Daphne occulted HIP 93026 on March 31, 2013 on the small Nikoi Island in Indonesia . Paul made a successful observation and his single chord was a very close match compared to the inversion model of Daphne.

On September 11, 2013 he observed 196 Philomela occult an m = 7.1 star HIP 2038 from Russia . Upon arrival, despite email issues (he had none), bank transfer and logistics problems he finally got a hotel. More logistics problems prevented him from observing inside the path. He observed from Sochi under clear skies , far from the path and had no occultation.

Scotty Deganhardt showed his Maxi Mount for use with the Orion 120mm short tube refractor. His mount is all sky accessible, has slow motion control for pre-pointing, stands 24” tall, all parts costs $100 and has a magnitude limit with the PC164-EC  of about +12.5.  The tripod is made from a Sears sprinkler tripod and Orion mini EQ Tabletop equatorial mount. He showed the parts list and photos of the assembly procedure of the mount. 

Scotty  next presented his continuing research of Jovian extinction events (JEE) and how he is able to model the Jovian dust field, moon atmospheres, flux tubes and Io’s Torus. This exciting new research begun when Scotty saw evidence for an atmosphere (dimming effects) for Io and Europa during an eclipse/occultation event August 9, 2007.  Since then he has been collaborating with Arne Henden (AAVSO) who correctly estimated the observations would reach a 0.015 mag standard deviation.  

Extensive observations seemed to show that Europa seems to show a 18-radii extinction  with a 0.25 magnitude drop as evidence. For Io they found an 8 Io radii extinction detection with an 0.18 magnitude drop. He showed slides illustrating how the extinction event is viewed from Earth to detect Io’s torus. Scotty even took the Hubble challenge from a professional planetary astronomer – could he detect Io’s torus as it transits Jupiter?  He was able to do it despite the non-uniform brightness of the disk of Jupiter in the background.

Scotty showed numerous light curves from extinction videos. The precision of the magnitude data showed standard deviations of 0.009-0.019 with S/N ratios ranging from 8.7-12.2, hence the detection of the “wings” on the light curves was quite simplified. The light curve fits to JPL ephemeris data was also very good. In 2014 Jupiter’s orbital plane reaches edge on hence a new series of transit/eclipse events begins. One of the goals now is to add spectral data to add multi-color date to the observations.  

The Nike occultation event was scrubbed due to cloud cover so David Dunham finished his presentation of multi-station deployment that he started yesterday.

  Sunday October 6

Brad Timerson presented a summary of asteroid occultation statistics for late 2012 and 2013. He showed histogram charts of the total number of observed events and no. of chords obtained for these events. A possible new satellite was observed for 2258 Viipuri on August 3, 2013.  Inversion models were shown for several asteroid events along with their corresponding occultation chords. The agreement was excellent in most cases except for 45 Eugenia on May 20, 2013 in which one southerly chord didn’t match the inversion model.

David Dunham continued with a list of future asteroid/planetary occultations for 2013 and 2014 and showed a list of “best” events in the RASC Observer’s Handbook. He showed some Occult maps of some of the major events involving brighter stars. A fantastic opportunity exists for the occultation mag +1.4 Regulus by 163 Erigone on March 20, 2014  over New York/Canada. 

Richard Nugent's YouTube page has an animation of the Regulus event as seen over the New York/Canada:

http://www.youtube.com/watch?v=kt__thK1Do8 

Another bright star event is by 3 Juno occulting the mag +7.4 star SAO 117176 will occur on November 20, 2014.      

David completed his talk on the RASC handbook lunar occultation and graze events for remaining 2013 and 2014. He showed the RASC table of grazing events for the rest of 2013 and the list for 2014. Graze maps were also shown for the same time periods for the USA/Canada.

Dave Herald presented his annual presentation of “Occultations from Around the World” from July 2012 through September 2013. Part 1 – lunar occultations observed by region: Japan led with 4,158 observations, North America had only 458 observations. Brian Loader reports that 254 double stars were observed which included 22 new discoveries. Part 2 – best asteroid events. 2012 and 2013 has seen a drop in the total no.of observations. Dave believes the drop is not due to people attempting events but rather the decreasing accuracy of predictions due to the declining precision of star positions and proper motion effects from catalog errors. Two possible satellite discovery profiles were shown  - 911 Agamemnon  from Jan 19, 2013 and Aug 3, 2013 by 2258 Viipuri.

Since June 2012, 7 new double stars were discovered. An interesting double discovered was on Aug 15, 2013 in Australia of the 611 Valeria occultation in which the time differential was 66 seconds. This wide double was estimated have a separation of 380mas.  He then showed several asteroid profiles obtained from the best observed events including 87 Sylvia in which one of its 2 known satellites was picked up by 2 chords.      

Dave next presented a new software program – AOTA for analyzing asteroid light curves. The program handles D and R events independently and uses cross correlation analysis with uncertainties using a Monte Carlo routine with noise effects applied to light curves. He showed an analysis of the 911 Agamemnon light curve’s possible satellite observation. The program’s analysis clearly shows that there was a real occultation of the possible satellite event rather than an atmospheric effect such as a cloud moving over. AOTA can plot up to 3 comparison stars and analyze up to 5 events in a light curve. AOTA’s output consists of  event time and uncertainty. Sub frame calculations are not done and conversion to time is currently not done due to camera and VTI characteristics. Dave’s future developments will include a direct interface with Tangra and of course future enhancements are based on user input.    

John Broughton next presented a self narrating talk “Asteroid Dimensions from Occultations”.  This talk is intended for all observers and John started by listing the main factors necessary to make an asteroid occultation observation including having a telescope properly pointed, a recorder going, problems with weather, path errors, etc. He showed how chords are “weighted” to determine asteroid sizes. John showed how timings were converted to chords, then event diameters, then mean diameters and finally converted to ellipsoids. John listed some of the most well determined profiles/mean diameters. ESA’a GAIA satellite offers promising new highly accurate star positions to offer highly improved path predictions. And with future large survey telescopes this will expand observations to Kuiper belt objects and TNO’s expanding occultation opportunities.       

12:10 PM EDT Lunch break

April Russell  from Dudley Observatory in Schnectady, NY talked about “Hands on Astronomy”. Her background and graduate work was in asteroid spectrometry, now she leads the  educational/public outreach with students at the observatory. She started with a short video about 3-D modeling and printing. NASA’s Night Sky Network actually suggested her starting students to learn about asteroids by making them out of clay. She showed a better way  by using 3-D shape models and printing them using 3-D printing  methods. A 3-D printed model of an asteroid would rise above the plane of the paper (like mountains on a globe). She showed the example of 135 Hertha, from observations to light curves to shape models to printed models. She continued to explain how a digital model is converted to printable form using texture, density to various cross sections of the asteroid using various 3-D printing technologies. 3-D printing machines range in cost of $500-$20,000+. Some companies offer 3-D printing services priced based upon volume and material the user wants. 

Ted Blank showed an animation of D and R’s for the asteroid occultation of the 90 Antiope double asteroid event from July 13, 2011. He used a program (After Effects ) to do these D and R animations. First he used a Google Map of the path area for the background, then plotted the positions of the observers (from their lat/long). He then choose a shape of the asteroid (oval, circle, ellipse) and made it move at real time rates across the map.Hits have observer’s points disappear with misses keeping their points at full brightness. Ted’s son was also involved in developing this project. 

David Dunham  discussed “Trying to Hit the Flat Areas of Grazing Occultation Profiles Using Kaguya Data”. He started by showing the basic geometry of grazes along with several profiles. Then he showed slides of the multiple station technique used on a few grazes starting with the Dec 21, 2001 tau2 Aqr graze. On April 10, 2011 he has a good success with mag +3.5 Eta Gem using Mighty Minis/Maxis. He then described the May 13, 2013 graze of an +8.9 mag star with a 8% sunlit waxing Moon just 17 degrees above the horizon in his home state of Maryland . He had only one D and R . According to Dr. Mitsuru Soma, the actual graze path had shifted due to in part from proper motion of the star. 

 

His next graze was on June 2, 2013 near Mozhayskoye in Russia with Vladimir Belousov . They observed a +4.5 mag star against the 37% sunlit Moon.   Vladimir obtained 3 D’s and 3 R’s . On August 2, 2013 he and Joan Dunham observed the graze of ZC 798 in the parking lot of Hanover High School , Mechanicsville , Virginia . His Station 1, prepointed had 6 D’s and 6 R’s. Joan, manually guiding her 8-inch telescope and observed at her station 8 D’s and 8 R’s !!!! A 3rd southernmost station was prepointed and got 5 D’s and 5 R’s. Unfortunately David’s 120mm Maxi at the southern edge got no events due to him not getting the telescope on target in time.  

 

David then summarized the ESOP 2013 meeting  presentations. David talked about the long history of double star discoveries from occultations and IOTA’s efforts to catalog probable and possible events from lunar occultations. IOTA’s recent double star efforts call for observers with video cameras with wide separations to help confirm these doubles. Several papers have been published in the Journal of Double Star Observations (JDSO) identifying new double star discoveries from both lunar and asteroid occultations.  He showed some slides on how professionals using larger telescopes and high speed photometric capability have discovered some double and triple star systems from lunar occultations.   

 

A video was showed of a Spica graze from November 30, 1994 with WWV audio that was later converted to digital with time insertion. This conversion uses the WWV tones to trigger  an internal quartz sub-second timer which is overlaid on the screen.  He then showed Steve Conard’s time inserted video showing a possible satellite of 911 Agamemnon  from Jan 19, 2013. Next was a video of a double star discovery from an asteroid event from Jan 2011.  

 

10 minute break

Tony George then presented “Integrating Video Cameras Operating Guidelines”. Many IOTA members have integrating video cameras to help reach fainter stars. Most common ones used by members are the WAT-120N+, PC165DNR, Minitron and the Mallincam. Tony stressed that it is the user’s responsibility to know your camera’s settings and how to use them – shutter control, gain settings, gamma functions, etc. Tony showed how to set the WAT 120N camera and showed screen shots of the PC165DNR settings. He recommended that you use the fastest possible shutter speed for best time resolution. Regarding gain control, he recommended a fixed max gain setting that would not saturate the star images. For color cameras, set them to B/W mode. Tony recommends if you are in doubt ask an expert on how to set your camera’s settings for maximum results.

Tony provided a list of resource people for questions on the various integrating cameras:

WAT 120N        ---   Tony George

Stellacam EX      --- Steve Conard, Ernie Iverson

PC165DNR        --- Ted Swift

Mallincam          ---  Tony George (tentative)

Minitron             --- John Meneke

Samsung SCB 2000    --- Terry Redding (tentative)

Brad Timerson presented “Timing analysis spreadsheet for Pre/Post Time Stamped Videos”. The technique was pioneered by Scotty Deganhardt for his multi-station technique using Canon digital (DV) camcorders. Digital camcorders have internal clocks that are not in sych with UTC and this error propagates. With help from John Talbot, Tony George and Brad came up with a Excel Spreadsheet and Word document describing the proceedure to compensate for this. This spreadsheet computes the actual UTC time of an event by converting  the internal times/frame #’s from an digital camcorder with a time stamp before and after the event.  With the frame(s) of the event identified in Limovie, the spreadsheet will calculate the UTC time of the event. Brad has a zip file which inclusdes a Word Document with examples on the North American Asteroidal webpage.    

Following this Door Prizes were given. Richard Nugent, David Dunham and Jan Manek are the lucky folks !!

Dr. Terry Redding talked about “Seeing More with Less”. Terry described how he educates students on how faint they can see events and how to plan for events. He tells students about the history of occultations, types of discoveries made (close doubles, asteorid sizes/shapes). He tells people what the plan is – have a telescope, record (preferably) with video, importance of timing techniques, preparing to travel and weather forecasts. He showed some of the cameras they could use – over the counter digital cameras such as Canon Powershot down to the PC164C and Mighty Minis.  He showed a few slides of some of his early occultation atempts, failures and what he learned, how Occult Watcher is used, using star charts,  filing reports, etc. In summary, Terry does not discourage anyone from attempting events regardless of  their experience, and/or availabilty of equipment.

The meeting ended at 5:15 PM.

                                                                                 

 

IOTA's Annual Meetings

The International Occultation Timing Association is the primary scientific organization  that predicts, observes and analyses lunar and asteroid occultations and solar eclipses.  IOTA astronomers have organized teams of observers worldwide to travel to observe  grazing occultations of stars by the Moon, eclipses of stars by asteroids and solar eclipses since 1962.