K\"onigstuhl 17, Heidelberg, D-69117 Germany
e-mail:apai@mpia-hd.mpg.de
2 Astrophysical Inst. and University Obs. Jena
Schillergässchen 2-3, D-07745 Jena, Germany
3European Southern Observatory
Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile
4 TLS Tautenburg
Sternwarte 5, D-07778 Tautenburg, Germany
Abstract:
We present the first mid-infrared (MIR) detection of a
field brown dwarf (BD) and the first ground-based MIR measurements
of a disk around a young BD candidate. We prove the absence of warm dust surrounding the
field BD LP 944-20.
In the case of the young BD candidate Cha Hα2, we find
clear evidence for thermal dust emission from a disk. Surprisingly, the object does
not exhibit any silicate feature as previously predicted. We show that the flat
spectrum can be explained by an optically thick flat dust disk.
