= we propose to record the first spectrum of a brown dwarf (gliese 229b) longward of 5 microns (4.9-12.2 microns), using the isocam instrument with the cvf. gliese 229b, a weak companion to the nearby m1 v star gl229a, is the only unambiguous brown dwarf discovered to date. its spectrum has been explored only in the 1- to 2.5-micron range, revealing spectral signatures from methane and water vapour. in the observations proposed here, we expect to detect strong absorption features from these two compounds between 5.2 and 8.2 microns and to make the first detection of ammonia from its nu_2 band at 10.5 microns. these observations will provide unique information on the thermal structure of gliese 229b, on its elemental c and o abundances, and ultimately on its age, mass, and evolution. this is a new proposal since the discovery of gliese 229b occured after the initial call for iso proposals.
Instrument
CAM01 , CAM04
Temporal Coverage
1997-10-24T04:35:46Z/1997-10-24T07:37:40Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
