DPS 34th Meeting, October 2002
Session 21. Pluto, Charon and Triton
Oral, Chair(s): M. Buie and P. James, Wednesday, October 9, 2002, 9:20-10:10am, Ballroom

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[21.01] The 20 July 2002 occultation of P126 by Pluto

B. Sicardy (LESIA, Paris Obs.), F. Colas (IMCCE, Paris Obs.), T. Widemann (LESIA, Paris Obs.), W. Beisker (IOTA Europe), C. Birnbaum (LESIA, Paris Obs.), K. Brooks, A. Delsanti (ESO), A. Fienga (IMCCE, Paris Obs.), E. Gendron (LESIA, Paris Obs.), O. Hainaut (ESO), M. Kretlow (IOTA Europe), A.-M. Lagrange (Grenoble Obs.), J. Lecacheux, C. Leyrat (LESIA, Paris Obs.), A. Maury (ESO), E. Raynaud (LESIA, Paris Obs.), M. Rapaport (Bordeaux Obs.), S. Renner, F. Roques (LESIA, Paris Obs.), M. Schultheis (IMCCE, Paris Obs.)

The star P126 was a candidate for occultation by Pluto on July 20, 2002, see the list of McDonald and Elliot, AJ 119:1999-2007, April 2000, and AJ 120:1599-1602, September 2000. Astrometric measurements from various sources, including Pic du Midi Observatory, predicted that the shadow path would sweep across the upper half of South America, with significant uncertainties, however, due to the duplicity of the star.

An observational campaign was organized using both large fixed telescopes and small portable stations in South America, with wavelengths spanning from the visible to the K band. Acquisition techniques ranged from classical fast imaging to IR adaptive optics imaging and low resolution visible spectroscopy. The involved fixed telescopes were the ESO 8.2-m VLT (Paranal, Chile), the ESO 3.6-m and 3.5-m NTT tel. (La Silla, Chile), the UCN 0.4-m tel. (Cerro Armazones, Chile), the Leoncito 2-m tel. (El Leoncito, Argentina), the CNPq 1.6-m and 0.6-m tel. (Pico dos Dias, Brazil) and the Observatorio Nacional 1-m and 0.65-m tel. (Llano del Hato, Venezuela).

Finally, mobile stations with refractors ranging from 20-cm to 35-cm in diameter were deployed in Northern Chile, central Peru and Ecuador.

Due to bad weather, technical problems and/or to the shift of the shadow path north of the initially predicted zone, only one positive detection of the occultation is reported, with a mobile 30-cm telescope near Arica, northern Chile (8d26m53.8s S, 69d45m51.5s W, alt. 2500 m). The lightcurve was acquired with an AUDINE camera using a KodaK KAF 400E CCD. The integration began at 1H42m UTC, with a drift scan speed of 10 line per second.

Preliminary analysis gives the mid-occultation time at 1h44m15s UTC. The duration of the event is 115 +/- 5 seconds with a flat lightcurve in the central 60 to 70 s.

More results will be presented as ongoing progresses are made in the reduction of the lightcurve.

We thank C. Angeli, A. Bruch, H. Calderon, R. Campos, S. Carrillo, A. Carvajal, L. Gaviria Cavero, D. Lazzaro, H. Levato, C. Montalve, O. Naranjo, L. Porras, E. Recalde, P. Rosenzweig, G. Rojas and U. Sanchez, who made these observations possible.

If the author provided an email address or URL for general inquiries, it is as follows:

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Bulletin of the American Astronomical Society, 34, #3< br> © 2002. The American Astronomical Soceity.