Bibcode
Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; Jehin, E.; Camargo, J. I. B.; Assafin, M.; Behrend, R.; Unda-Sanzana, E.; Colque, J. P.; Morales, N.; Tancredi, G.; Roland, S.; Bruzzone, S.; Salvo, R.; Almenares, L.; Emilio, M.; Schoenell, W.; Gil-Hutton, R.; Milone, A.; Jacques, C.; Vanzi, L.; Kavelaars, J. J.; Cacella, P.; Maury, A.; Alvarez, E.; van der Bliek, N. S.; Vieira-Martins, R.; Colas, F.; Lecacheux, J.; Vachier, F.; Roques, F.; Widemann, T.; Thirouin, A.; Gillon, M.; Manfroid, J.; Bergengruen, A.; Martinez, M.; Capeche, J.; Amorim, A.; Pimentel, E.; Leiva, R.; Toledo, I.; Almeida, L. A.; Magalhães, V. S.; Montaña, C. E.; Rodrigues, C. V.
Bibliographical reference
EPSC-DPS Joint Meeting 2011, held 2-7 October 2011 in Nantes, France. http://meetings.copernicus.org/epsc-dps2011, p.1060
Advertised on:
10
2011
Citations
5
Refereed citations
4
Description
Between February 2010 and May 2011, our group has observed five stellar
occultations by Trans-Neptunian Objects (TNOs), giving the size and
shape for some of the biggest TNO's: Varuna, Eris, 2003 AZ84, Makemake
and Quaoar. Here we present two of them: the January 08 stellar
occultation by 2003 AZ84, and the May 04 by Quaoar. For the event of
2003 AZ84 we obtained one positive and another negative occultation
chords in Chile. We give a lower limit to the diameter of the TNO. The
event of Quaoar was observed from 16 sites distributed in Uruguay,
Argentina, Chile and Brazil. Five of them yielded positive detection of
the occultation. A preliminary analysis shows that the body is probably
elongated and significantly bigger than the size determined by Fraser
& Brown 2010, with a diameter of 890km. Using the size determined by
the occultation, we will discuss the implications for the body density
and albedo determination. The upper limit of the atmosphere is also
studied.