On the evening of Monday June 12 UT Pluto (and P2, one of its two newly-discovered satellites) will occult the 15th magnitude star UCAC 2603 9859. The shadow of Pluto will sweep across all of New Zealand, Tasmania, ACT, and Victoria, with the central line of the occultation shadow passing very close to Christchurch, NZ and Mt John Observatory at Lake Tekapo. The latest prediction by Bruno Sicardy (Observatoire de Paris-Meudon) is shown here:

Also shown is the predicted path of the occultation by Pluto's satellite P2, whose diameter is expected to be only ~100 km.

Only two significant occultations by Pluto have been previously observed:

• 1988 June 9: Observed from New Zealand, Australia and the Kuiper Airborne Observatory, during which Pluto's atmosphere was discovered and its extent estimated;
• 2002 July 20: Observed from South America

The extent of Pluto's atmosphere has changed markedly as it has drawn further away from the Sun since 1988, making observations of the 2006 occultation critical in further estimating its rate of decay, as well as its other characteristics. Given the very recent discovery of satellite P2 and the difficulty in estimating its parameters, observing an occultation by that body is expected to provide valuable data on the satellite's physical characteristics. All of the data gathered during this event will be of assistance to NASA's New Horizons mission to Pluto which was launched on 19 January 2006.

The 2006 June 12 occultation will be observed by a wide variety of professional and semi-professional groups who have acquired time on most of the large telescopes in the region. These include observers from Lowell Observatory, MIT, Williams College, Paris Observatory and elsewhere. In addition, a number of amateur astronomers throughout Australia and New Zealand will attempt the event, although results are only expected from telescopes of moderate to large aperture given the 15th magnitude star's proximity (about 15 degrees) to the near full Moon.

A full overview of the event, including finder charts, is given on Wolfgang Beisker's excellent page:

http://www.iota-es.de/pluto384.html

Detailed information about individual preparations being made within Australasia are available on the:

RASNZOccultations Yahoo Group.

Dave Gault's trial photo (10 inch Newtonian; Meade Deep Sky Imager; unfiltered one second exposure) of the Pluto/P2 target taken in May (in an effort to mimic the conditions expected on the 12th June):

http://www4.tpgi.com.au/users/daveg/060514_Plutofield_1sec.gif.

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