[IAUC] CBET 2675: 20110312 : STELLAR OCCULTATION BY TRANSNEPTUNIAN OBJECT (208996) 2003 AZ84

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                                                  Electronic Telegram No. 2675
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


STELLAR OCCULTATION BY TRANSNEPTUNIAN OBJECT (208996) 2003 AZ84
     F. Braga-Ribas, B. Sicardy, F. Colas, and J. Lecacheux, Observatoire de
Paris; A. Maury, San Pedro de Atacama Celestial Explorations Observatory
(SPACE); J. L. Ortiz, N. Morales, and I. de la Cueva, Instituto de Astrofisica
de Andalucia (IAA), Granada; E. Jehin, J. Manfroid, and M. Gillon, Institut
d'Astrophysique de l'Universite de Liege; M. Assafin, Observatorio do Valongo,
UFRJ, Rio de Janeiro; and R. Vieira-Martins and J. I. B. Camargo, Observatorio
Nacional, Rio de Janeiro, report on the positive detection of an occultation
of a faint star (magnitude R about 18) by the transneptunian object (208996)
2003 AZ84 on Jan. 8d06h29m59s UT (mid-time), from the SPACE Observatory.  The
occultation was recorded by A. Maury with the C. Harlinten 0.5-m Planewave
telescope there, and also by J. L. Ortiz with the remotely operated 0.4-m
ASH2 telescope of the IAA in Spain.  E. Jehin and J. Manfroid report that no
drop of the flux was observed with the 0.6-m robotic TRAPPIST telescope of
Liege University, which is located 610 km from San Pedro.  Using a
diffracting model, F. Braga-Ribas determined the times of immersion and
emersion of the star.  The occultation lasted for 21.7 +/- 0.8 seconds,
corresponding to a chord length of 573 +/- 21 km.  This result gives a lower
limit to the diameter of the TNO, and can be compared to the estimated
diameter from Stansberry et al. (2008, *Physical Properties of Kuiper Belt
and Centaur Objects*, University of Arizona Press, pp. 161ff; 685.8 +/- 95.5
km, based on Spitzer data) and Mueller et al. (2010, A.Ap. 518, L146; 910
+/- 60 km, based on Herschel data).


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                         (C) Copyright 2011 CBAT
2011 March 12                    (CBET 2675)              Daniel W. E. Green