From Dr J. Lecacheux, Meudon Observatory, France:

Dear occultation observers in Australia, New-Zealand and south Pacific:

The binary system of 22 Kalliope is very important, as its dynamic properties (precession of satellite orbit, fast rotation in P=4.15 hours) are related to its density and to its internal structure.

As you know, the coming May 14 occultation of the 11.3 magn. star TYC 6816 87 will cross Australia, namely the north part of New South Wales. Steve Preston has issued a good prediction update (only for the central body).

F.Marchis at Berkeley University, working with a team of the IMCCE (alias 'Bureau des Longitudes', Paris) has followed the ~20-km satellite of Kalliope with adaptative optics since its discovery epoch, using first the 3m-telescope at Lick, then the VLT and Keck more recently. So they have obtained a very accurate solution for the orbit, and from recent measurements (yet unpublished) they are able to predict the probable satellite path on May 14.

On the following figure [ed: refer our main Kalliope page], the blue curve is the predicted occultation path of the Kalliope "moonlet" according to the IMCCE. It should cross the Queensland coast near the town of Rockhampton. The parallel red curves correspond to the main asteroid (north and south limits) and are close to S.Preston's solution. Occultation paths of Kalliope and its satellite

We expect some improvements shortly (i.e. better link with main body update(s), table of geographic coordinates, accuracy estimation).

We contact also 2 or 3 french speaking observers in Tahiti island, in the central Pacific, which also will be close to the predicted path, probably northside.

It would be a very nice thing (the first time in Astronomy !), if any occultation observer in Australia would move to the predicted "blue" track, and catch the brief star extinction by the asteroidal satellite.

Besides the astrometrical interest and fun (a position measurement better by a factor 10-30 than available with 8-10 meters telescopes), this result might be very useful also to us, as another occultation by the Kalliope system is expected in Europe on June 05, only 3 weeks later. We plan similar expedition(s) to intercept the small Kalliope companion, and so any preliminary detection on May 14 could improve our chance of success greatly.