Volume 480, Number 2, March III 2008
|Page(s)||543 - 550|
|Section||Planets and planetary systems|
|Published online||17 January 2008|
174P/Echeclus: a strange case of outburst*
University of Franche-Comté, Observatoire de Besançon, Institut UTINAM – UMR CNRS 6213, BP 1615, 25010 Besançon Cedex, France e-mail: firstname.lastname@example.org
Accepted: 7 December 2007
Context.More than ten Centaurs are now known to have cometary activity at large heliocentric distance (i.e. 5-13 AU). Among these objects, 174P/Echeclus which showed cometary activity at 13 AU from the Sun, is a unique case, because of: (i) the amplitude of its outburst, (ii) the source of cometary activity that appears distinct from Echeclus itself.
Aims.This paper aims at investigating the physical conditions that have led to this unusual outburst. The purpose is also to quantify this phenomenon and to provide observational constraints for its modeling.
Methods.We use observations from different telescopes, performed before, during, and after the outburst. We performed the main observations on March 23 and 30, 2006, with the 8.2-m ESO Very Large Telescope and FORS 1 instrument. They consist of visible images and spectra.
Results.Our main results are: (i) a cometary source distinct from Echeclus itself that presents a brightness distribution compatible with a diffuse source; (ii) a total dust production rate Qdust 86 kg s-1 and a parameter 10 000 cm; (iii) no emission lines (CN and C2) can be detected in the visible range; (iv) the upper limits for the CN and C2 production rates are 3.81025 and 1026 molecules s-1 respectively; (v) we detected no Echeclus' satellite before the outburst up to MR 26; (vi) the upper limit for the object generating the coma is about 8 km in diameter; (vi) and we detected no cometary activity one year later, in March 2007.
Key words: comets: general / comets: individual: 174P/Echeclus / Kuiper Belt / solar system: general
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.