The Deuterium Test for Exo-Planet Candidates Detected Directly

Ralph Neuhäuser, Andreas Seifahrt, Peter Hauschildt, Joao Alves, Eike Guenther

In the near future, direct images will be obtained for massive planets

orbiting around other stars. Most likely, the first such objects

detected directly will have masses near the proposed limit between brown

dwarfs and planets, i.e., around 13 Jupiter masses, because the more

massive planets are the brightest. Hence, it may be dubious in these

first few cases, whether the detected object is a brown dwarf or a real

planet. To solve this problem, one can perform the deuterium test, i.e.,

one can distinguish between a brown dwarf (defined as an object able to

fuse all deuterium) and an real planet (defined as an object not being

able to fuse any deuterium) by whether or not deuterium can be

identified in a spectrum. Any such object, brown dwarf or planet, would

have spectral type T, defined as those with strong methane lines in the

infrared. We present a model spectrum with the CH3D line at ~ 4.5 μm

which can be obtained for such objects with CRIRES at the VLT.

Department of Astrophysics
External organisation(s)
Friedrich-Schiller-Universität Jena
Publication date
Austrian Fields of Science 2012
103004 Astrophysics
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