Um modelo híbrido para a poeira cometária

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

25/02/2011

RESUMO

In this Work, we present a systematic and uniform study involving the productivity of Comet 67P/Churyumov-Gerasimenko, target of ROSETTA Mission, during the 1982, 1996, and 2002 apparitions. Gas mass production rates [in g s-1] are obtained using hydroxyl radical (OH) rates [in molecules s-1], given in literature, considering that ~ 85% of the water photodissociation lead to OH radical (HUEBNER, KEADY &LYON, 1992). In turn, dust mass release rates [in g s-1] are deduced using a model which combines the Photometric Model structure, given by NEWBURN &SPINRAD (1985, 1989), with the A´HEARN´S MODEL (A´HEARN ET AL., 1984). The Hybrid Model, here introduced, converts Afr parameters [in cm] into dust mass release rates [in g s-1], and determines several physical properties associated to grains, such as effective sizes, velocities, blackbody associated temperatures, colors and also dust-to-gas ratios as well as its variations with heliocentric distance. For the 2015 perihelion [r = q = 1.24 AU, in 12 August, 2015], we find that Comet 67P/Churyumov-Gerasimenko will lose mass as gas and dust at a rate of 405 kg s-1.

ASSUNTO(S)

poeira cósmica - propriedades físicas massa (física) comets cosmic dust physical properties mass (physics) cometas

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