Proceedings of Ceres 2001 Workshop October 9-12, 2001 Paris, France Institut de Mécanique Céleste et de Calcul des Ephémérides Observatoire de Paris Dépôt légal : février 2004 ISBN : 2-91015-43-2 © IMC Editions Foreword You will find herewith the proceedings of the workshop Ceres 2001 organized in honour of the bicentenary of the discovery of Ceres by Piazzi and dedicated to astrometry and physics of asteroids thanks to observational networks. We are glad to present here these proceedings : the contributions of the participants covered all the topics of the workshop. They deal with celestial mechanics and physics of the asteroids and also with theoretical and observational studies. The progress of our knowledge on aste- roids needs to investigate simultaneously these topics. The efficiency of the observational networks has been put into light and the need of an improved astrometric accuracy was demonstrated as a necessary step for new discoveries. The determination of the masses of the asteroids, the interpretation of the observations of occultations, will be improved thanks to high accurate astrometric observations, together with photometric measurements. Then we will be able to reach information on what are the asteroids and what are the composition and the evolution of the solar system. We hope that discussions have been helpful for the participants and that collaborations have started among them. 3 Acknowledgements We wish to thank here all of those who contributed to the success of the workshop, and in particular the scientific organizing committee and the local organizing committee : Mrs Baron, Derouazi, Martinez, Raoult, Simon, MM. Mulo, Renaudineau, Vaubaillon for the organization of the meeting and Mrs S. Lemaître-Pottier for the making of the proceedings. We also wish to thanks the chairperson of the sessions and of the discussions who allowed the workshop to be fruitful and interesting. We are indebted to the members of the organizing committee who read carefully all the sub- mitted papers before publication and we thank all the participants for their contribution. Special thanks are for the organisms which help us for the meeting: scientific council of Paris observatory for a financial support, Institut d’Astrophysique de Paris for their welcome in their building, Museum National d’Histoire Naturelle for their kind invitation and the DFI Group for the loan of computer terminals. J.-E. Arlot and W. Thuillot eds 5 Organizing committee J.-E. Arlot (1) (chairman), M.-A. Barucci (2), C. Blanco (6), J. Berthier (1), F. Colas (1), D. Hes- troffer (1), J. Lecacheux (2), J. Renaudineau (1), D. Simon (1), P. Tanga (3,5), W. Thuillot(1), A. Vienne (1,4). 1- IMCCE, Observatoire de Paris 2- LESIA, Observatoire de Paris 3- Observatoire de Turin 4- Université de Lille 5- OCA 6- Institut d’astronomie de l’université de Catane 7 Astrometry and physics of minor planets from observational networks Organized by Institut de mécanique céleste et de calculs des éphémérides, observatoire de Paris, the Ceres 2001 workshop, dedicated to the discovery of Ceres by Piazzi in 1801, gathe- red professional and amateur astronomers, theoreticians and observers, interested in asteroids and more generally in small bodies of the solar system, modeling motions, looking for physical properties of these objects and observing through common networks. This workshop permit also to review the techniques used at the present time for the observations of asteroids. Topics were : • astrometric observations of the asteroids : towards a better accuracy ; • prediction and observation of occultations of stars by asteroids : increasing the efficiency of the networks of observers ; • photometric observations of the asteroids : determination of rotation and poles, modeling the figure of the asteroids ; • search for satellites of asteroids, for binary asteroids : detection of new systems ; • observation of the other small bodies of the solar system : improvement of the dynamical models • networks of observers. The present proceedings provide the communications presented during the workshop. Astrométrie et physique des petites planètes grâce aux réseaux d’observateurs L’atelier de travail Cérès 2001, organisé par l’Institut de mécanique céleste et de calculs des éphémérides, observatoire de Paris, était dédié à la découverte de Cérès par Piazzi en 1801. Il a rassemblé des astronomes professionnels et amateurs, observateurs et théoriciens, intéressés par l’étude des astéroïdes et plus généralement par celle des petits objets du système solaire, la modélisation des mouvements, la détermination des paramètres physiques et utilisant les observations réalisées par les réseaux d’observateurs ou y participant. Cet atelier de travail a permis également de discuter des techniques actuellement utilisées pour ces observations. Les sujets traités ont été : • les observations astrométriques des astéroïdes : vers l’amélioration de la précision ; • les prédictions et observations des occultations stellaires : comment accroître l’efficacité des réseaux d’observateurs ; • les observations photométriques d’astéroïdes : la détermination des pôles de rotation, la morphologie des astéroïdes ; • la recherche des satellites d’astéroïdes et des astéroïdes binaires : vers la détection de nou- veaux systèmes ; • l’observation des autres petits objets du système solaire : vers un amélioration des modèles dynamiques ; • les réseaux d’observateurs. Le présent volume des comptes rendus contient les communications faites pendant cet atelier de travail. 9 Table of contents / Table des matières The discovery of Ceres by Piazzi in 1801 (abstract) . 15 Fodera Giorgia Hegel and the discovery of the asteroids . 17 Rapaport Michel K.E. Edgeworth and TNOs . 19 McFarland John Asteroid models from disk-integrated photometry . 25 Kaasalainen Mikko Photometric observations of asteroids : rotational period, lightcurves, spin axis and shape deter mination . 33 Blanco C., Cigna M., Riccioli D. Flux Preserving Regularization (FPR) method of restoration . 41 Bratsolis Emmanuel, Sigelle Marc CCD photometry of asteroids carried out at Poznan Observatory (Poland) . 47 Michalowski T., Kwiatkowski T., Kryszczynska A., Hirsch R., Bartczak P., Michalowski J. CCD lightcurves of several asteroids during their last apparitions . 51 Apostolovska Gordana, Borisov Galin ADAS : Asiago-DLR Asteroid Survey . 55 Barbieri Cesare, Calvani Massimo, Claudi Riccardo, Hahn Gerhard, Hoffmann Martin, Mottola Stefano, Pignata Giuliano, Salvadori Luciano Shape Determination of the Asteroid (6053) 1993 BW1 (Poster) . 61 Durech Josef What can we learn from the lightcurves of freely precessing asteroids? (Poster) . 63 Kryszczynska Agnieszka, Kwiatkowski T., Breiter S. Asteroid density; an overview . 65 Birlan Mirel Eight Years Observing Asteroidal Appulses to Stars . 71 Casas Ricard 11 Parameters of catalogue orientations as obtained from observations of the selected minor planets at Nikolaev Astronomical Observatory . 75 Gudkova L. A. Photographic and CCD Observations of Minor Planets from Valencia Observatory . 81 García Alvaro López , Moraño Fernández Jose A., Yagudin Leonid, Martínez Angel Flores Estimating masses of asteroids . 87 Krasinsky G.A., Pitjeva E.V., Vasilyev M.V., Yagudina E.I. Accuracy of world positional CCD observations of the numbered minor planets in 1999-2000 yrs . 93 Bykov O.P., L’vov V.N., Izmailov I.S., Sumzina N.K. Ceres : A true Minor Planet . 105 Christou Apostolos Limited accuracy of asteroids track estimation at observations with CCD detectors . 109 Biryukov Vadim, Rumyantsev Vasilij New method for asteroid identification with the use of Pulkovo apparent motions parameters . 115 Bykov O.P., Komarova N.O. Triumph of the Laplacean ideology for preliminary orbit determination in the CCD epoch (Poster) . 119 Bykov Oleg Asteroid photometric center determination (poster) . 121 Grynko Yevgen, Shkuratov Yu On the displacement of asteroid photocentre due to surface scattering (poster) . 123 Lupishko D.F., Tungalag N., Shevchenko V.G. Oservational programs for asteroid mass determination . 125 Thuillot W., Bec-Borsenberger A., Rapaport M., Arlot J.-E., Bange, J.-F. Single nignt positional CCD observations of unknown celestial body : what’s a problem? . 131 Bykov O.P. The Lowell asteroidal database and the future evolution (abstract). 137 Bowell E.L.G. Observational network : the mutual events observations . 139 Arlot J.E. 12 Proceedings of Ceres 2001 Workshop Facilities of the Bulgarian National Observatory for astrometric and photometric observations of asteroids . 143 Ivanova V., Shkodrov V., Apostolovska G., Borisov G., Bilkina B. The natural satellites astrometric observations datbase NSDC (abstract) . 149 Arlot J.E., Baron N. Agrupacio Astronomica de Sabadell : Our work in the field of the asteroids (poster) . 151 Casas Ricard Physical investigations of asteroids in Shemakha Astrophysical Observatory (poster) . 153 Shestopalov Dmitry The recovery as an important part of NEA astrometric follow-up (poster) . 155 Ticha J., Tichy M., Kocer M. Parameters of apparent motion of asteroids which collide with the Earth . 157 Rumyantsev V.V. On sky scanner-telescope efficiency (poster) . 163 Shestopalov Dmitry The Crimean CCD telescope for the asteroid observations . 165 Chernykh N.S., Rumyantsev V.V. Near-Earth Asteroids and Their Interest . 171 Binzel Richard The use of radar observations of Near-Earth Asteroids for different astrometrical purposes . 173 Yagudina Eleonora I. Kuiper Belt Objects photometry and position measurements