The stellar occultation by Makemake on 2011 April 23

José Luiz Ortiz (1) , Bruno Sicardy , Marcelo Assafin (2) , Alvaro Alvarez-Candal (3) , Valentin D. Ivanov (3) , J. I. B. Camargo (4) , Stuart P. Littlefair (5) , E. Unda-Sanzana (6) , Emmanuel Jehin (7) , F. Braga-Ribas , Emmanuel Lellouch , Nicolas Morales , Javier Licandro , Ricardo Gil-Hutton , René Duffard , J. P. Colque , Gonzalo Tancredi , J. Mafroid , Audrey Thirouin , Jean Lecacheux , Michel Gillon , Alain Maury , François Colas (8) , C. Jaques , D. Weaver , A. C. Milone , S. Salvo , S. Bruzzone , F. Organero , Raoul Behrend , S. Roland , Roberto Vieira Martins (8) , Thomas Widemann (8) , Françoise Roques , Pablo Santos-Sanz , Daniel Hestroffer (8)

1 Instituto de Astrofisica de Andalucia-CSIC, Solar System Department, Granada, Spain
2 Observatório do Valongo, Universidade Federal do Rio de Janeiro
3 European Southern Observatory, Chile
4 Observatorio Nacional / MCT, Brazil
5 Duke University [Durham]
6 Instituto de Astronomia, Universidad Catolica del Norte
7 University of Liège
8 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides

We have taken advantage of a stellar occultation by the dwarf planet Makemake on 2011 April 23, to determine several of its main physical properties. We present results from a multisite campaign with 8 positive occultation detections from 5 different sites, including data from the 8-m VLT and 3.5-m NTT telescopes in Chile, which have very high temporal resolution. Because the star was significantly fainter than Makemake (setting a record in the magnitude of a star whose occultation has been detected), the occultation resulted in a drop of just ~0.3 mag in the lightcurves. From the lightcurves we have been able to determine the size and shape of the body, its geometric albedo and constraints on its atmosphere.

Domaines: Astrophysique [astro-ph]

José Luiz Ortiz, Bruno Sicardy, Marcelo Assafin, Alvaro Alvarez-Candal, Valentin D. Ivanov, et al.. The stellar occultation by Makemake on 2011 April 23. AAS/Division for Planetary Sciences Meeting #43, Oct 2011, Nantes, France. pp.704. ⟨hal-03802861⟩