Astrolunch - 26th July

George Georgevits :
Detection of Sub-Kilometre Radius KBO's (Kuiper Belt Objects) by Stellar Occultation - 7,000 Star-hours Logged Using UKST - Preliminary Results

Using the unique capabilities of the 1.2m UK Schmidt Telescope (Anglo Australian Observatory, Siding Spring, Australia), in conjunction with the 6df Spectrograph (set up in straight-through mode), and by simultaneously monitoring ~100 suitably selected stars at a time, we were able to embark upon an occultation observation program which yielded ~7,000 hours of stellar light curves, with ~10 millisecond resolution.

The observation program was conducted over 16 nights during bright of moon periods in mid 2005. The initial data reduction indicates that we have captured many events which bear the hallmarks of occultation events, in so far as the light curves of recorded events typically match that which may be expected when a small KBO occults a suitable distant star.

Most logged events are spread over many pixels, with 10 pixels (corresponding to 100 milliseconds) being the typical event duration. By imultaneously monitoring many stars in the same field, observation artefacts such as those caused by close-in earth bound objects are readily eliminated.

It is concluded that the bulk of the events logged are consistent with events which would be caused by distant sub-kilometre radius KBO's (typically at ~40AU). Statistical analysis of the reduced data (so far!) supports this conclusion.