Science

discussion

Exocomet transits - would they be visible?

Started by AndyParsley
Default_user
over 6 years ago

Reference article: http://www.bbc.co.uk/news/science-environment-20954899

Would we see exocomet in Kepler's lightcurve data? I know comets are small but if the tail is long when close to the star then I was wondering if the amount of light blocking would be detectable in transits. If so what would the transit signature look like?

Default_user
over 6 years ago

From what I've read I believe very large comets might be visible, but I'm no expert. Perhaps the science team could answer your question.

Default_user
over 6 years ago

Even very bright comets like the Great Comet of 1882 were totally invisible (from Earth) when their heads transited the Sun, and comets' tails are so tenuous that they wouldn't have any detectable effect on a star's apparent brightness.

Default_user
over 6 years ago

As Tony pointed out, comets are very small and we only see them in our solar system because they brighten up sublimating ices as they head towards the Sun and become much brighter in the process. Comets are very small and Kepler has sensitivity to detect Venus sized planets, so individual comets passing in front of the star won't be detectable. I believe that even if the comets were in a disk, the disk would be so thin we would not detect any signal from it in the Kepler data.

Cheers,

~Meg

Default_user
over 6 years ago

Thanks alien333, Tony and Meg!

Default_user
over 6 years ago

There are other ways to detect belts of exocomets or debris disks. There have been a few discoveries of those presented at the American Astronomical Society meeting this week. You can read about it here.

Cheers,

~Meg

Default_user
over 1 year ago

Hi Andy, here we are fast forward to August 28, 2017 and you were very astute with your question on detecting exocomets by their tails four years ago. Check out exocomets on arXiv.org tomorrow.

Tom Jacobs

Default_user
over 1 year ago

Okay, it is really August 21st Solar eclipse day August 21st! The science paper will be out tomorrow.

Tom

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