Bibcode
Tozzi, Gian-Paolo; Boehnhardt, H.; Licandro, J.; Patriarchi, P.; Schulz, R.; Stüwe, J.; Vincent, J.
Referencia bibliográfica
American Astronomical Society, DPS meeting #41, #37.03
Fecha de publicación:
9
2009
Número de citas
0
Número de citas referidas
0
Descripción
Comet 67P, the target of Rosetta mission, was observed in the visible
and near-IR spectral regions during its perihelion approach. The
observations were performed in four epochs, at heliocentric distances
varying from about 3 to 1.4 AU, i. e. in the same range of the Rosetta
mission. The aims of the observations were the study of the dust coma
and its evolution with the distance from the Sun.
Results show the presence of a narrow tail and a faint coma at 3 AU.
Later the tail disappeared and an intense dust coma started developing.
The coma showed a strong increase of density in its inner part, close to
the nucleus. This increase cannot be explained with the presence of
sublimating grains, because the sublimation rate appears to decrease as
the comet approaches the Sun. A possible scenario is a coma constituted
by big grains that expand very slowly, with a projected velocity of the
order of 0.5 m/s. In the presentation we discuss all possible
alternatives, showing that the latter scenario is the most probable.