23 Oct 2013

Dazzling comet ISON may be dying, says study


 
Comet ISON photographed by the Hubble telescope.File photo: NASA/Reuters
Comet ISON photographed by the Hubble telescope.File photo: NASA/Reuters
Comet ISON – predicted to be one of the brightest comets of the century – may actually be disintegrating, according to a new study.
Astronomer Ignacio Ferrin, from the Universidad de Antioquia, analysed the most recent observational data of Comet ISON and has identified clear signatures of what he has called an “impending demise” of the comet.
The so-called light-curve of the comet shows features previously observed in disintegrating comets.
Despite the generalised scepticism and claims about the fact that the rumours of comet ISON “fizzling” were greatly exaggerated, the comet is still showing an unexpected behaviour that cometary specialists are fighting to explain.
“The light curve of the comet exhibited a slowdown event characterised by a constant brightness with no indication of a brightness increase tendency,” he said.
This slowdown began around January 13, 2013, and it continued up to the latest available observations at the end of September, this year, Ferrin said.
The brightness has remained practically constant for more than 270 days or 9 months, a behaviour without any precedent in cometary astronomy.
These evidences have led Ferrin to conclude that it is probably that the “comet is dying“.
In a recent letter posted to Cornell University arXiv preprints repository, Ferrin presented and discussed what he identified as a peculiar photometric signature previously observed in disintegrating comets.
“When I saw this signature I immediately went to my database of comet light curves, and found that two comets had also presented this signature: Comet C/1996 Q1 Tabur and comet C/2002 O4 Honig; to my surprise these two comets had vanished turning off or disintegrating,” he said.PTI

Courtesy with: THE HINDU

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