Bibcode
Tozzi, Gian-Paolo; Brucato, J. R.; Patriarchi, P.; Licandro, J.; Mazzotta Epifani, E.; Snodgrass, C.; Vincent, J.
Bibliographical reference
American Astronomical Society, DPS meeting #42, #28.19; Bulletin of the American Astronomical Society, Vol. 42, p.963
Advertised on:
10
2010
Citations
0
Refereed citations
0
Description
Comet Lulin was observed in July 2008, when the comet was in-bound at
1.7 AU from the Sun. Analysis of the images showed that the comet had a
very intense and anomalous enhancement of the column density of the
solid components in the inner coma. This effect was before interpreted
as due to the presence of sublimating grains (Tozzi et al, 2004, AA,
424, 325; 2007, 476, 979) or, more recently, to a developing coma
expanding very slowly (few meters per second, Tozzi et al. 2010,
submitted). To disentangle the two phenomena the comet was re-observed
in two epochs around its perihelion (Jan - Mar. 2009), when it was at
about 1.40 AU from the Sun and at about 0.4 AU from the Earth. In this
case the enhancement in the inner coma had disappeared, showing only a
wide but less intense enhancement at about 20000-30000 km of projected
distance. A possible contamination of gas, that would produce a similar
effect, has been excluded by spectra and observations with narrow band
filters centred in spectral regions without gas emission. In the
presentation the results of the analysis with possible interpretations
will be given.