This post is one in the category “I know that dude”.

Fomalhaut is one of the brightest stars in the night sky, and a young star known to have a circumstellar disk around it. Hubble images have shown a fairly sharp inner edge to that disk, suggesting that a planet is keeping the dust belt in check. There’s been claims about direct imaging of a planet with Hubble, but that claim has been somewhat controversial.

Dust absorbs light of all sorts of wavelengths, and emits itself at infrared wavelengths. The dust disk of Fomalhaut is thus an ideal target for the Herschel space observatory. Bram Acke analyzed those observations. Bram is one of those fine, young Belgian astronomers that is also involved in oureach, and that likes playing music.

As is often the case, the dust properties inferred from those new observations at far-IR wavelengths were at first sight not compatible with those inferred from the Hubble Space Telescope. Fortunately, Bram is a smart guy and he figured it out: the dust must be fluffy, like dust particles ejected from comets. It also implies that comets must be colliding there all the time!

Another example of cool science at long wavelengths!

You can find the ESA press release here:

http://www.esa.int/export/esaSC/SEM1XBHWP0H_index_1.html