An Idea for a cheap adaptor and app to help more of the general public participate in accurate asteroid occultation recordings. Tom Case Walnut Creek, CA Page 1 Mirror or Prism IPhone Adaptor Lens Binocular Objective Side View

“Top” View

Close up of possible optics. Tiny condenser lens is probably required flush to the iPhone Adaptor Lens First Focal Plane iPhone CCD plane

Pre Pointing Help Tracking and identification of field stars Arrows help guide adjustments until you are on the pre-point spot Pre-pointed, App takes over from here and records the light- curve. Possibly of a small moving sub-field

Just for yuks, a 2 minute masking tape mockup (Don’t laugh too hard) Three Axis Bogen Camera Mount Spotting Scope Lens, Mostly Hidden in this view iPhone

HOW MY DREAM OCCULTATION APP WORKS (with the attached optics shown) 1: The app alerts me a few days before of upcoming paths nearby. 2: I tell it how many hours before the event to wake me up. 3: At the viewing site I use a typical star finder program to point me approximately to the right area of sky, then attach optics to the iphone and the combination to the tripod, pointed approximately right. 4: The app starts taking long exposures, zoomed as far out as possible till it finds 2 or more stars. (It knows the exact orientation and magnification of the field of view from the drift motion of those stars). 5: It then fits these stars to a data base of FOV stars and finds the current pointing direction. (Magnitude ratio, distance and angle between the stars should be a clean signature) 6: It then draws an arrow on the screen to the correct pre-point location. This arrow is annotated with a multiplier saying how many “arrow- lengths” to the pre-point position. 7: The user then moves towards the pre-point position iteratively till it is centered as a bulls-eye on the screen. 8: The app then waits till a few minutes before the event, then starts recording. (It could even be a subfield at high rate) continued>

<continued from previous slide 9: The app then produces a light curve in standard format and sends it and GPS coordinates to the central occultation site. 10: Brad gets a faster computer to fit 500 chord 3D models of asteroids “rolling” across the earth as the “general public” picks up the rotating shadows with precision.

Some Guesses/Technical Notes/And comments 1: The missing link for me is: Can a good app programmer access all iPhone camera functions? Exposure time/ Focus/ Zoom/ SubField readout? If you have all of that you really can do ALL of the things mentioned above. If you have to let Apple pick your focus and exposure, give up now. 2:Don’t anyone worry about the quality of focus on the little condenser. Remember that too-good-of-focus can cause saturation. And remember that Kepler, intentionally runs out of focus for this and pixel averaging reasons. 3:I would add $100 to a pool to pay an apps programmer to work on a minimal version of this. Such a toy would get me and many of my friends out quite often and I think this would apply everywhere. Most people I have interviewed would get lost in finder charts. And one could have a borrowing library of the optics and mounts? Just pay the FedEx charge.

That’s all for now.. I have some more ideas for next time. Sorry about the weather.. My iPhone weather app tells me you got clouded out TC