GM Auriga and DM Tauri are pre-main sequence stars, aged 10 million years, similar to the Sun when it was young enough to be still surrounded by the protosolar nebula. Thus, studying these stars gives a unique opportunity to understand the infancy of our solar system. The millimeter observations of GM Aur and DM Tau show they are surrounded by a flat disk, from which future planets may form.

 

Spectra on the left : Millimeter spectra of several molecules observed with the 30m telescope in DM Tauri. For the first time, organic molecules have been observed in a protoplanetary disk, allowing to estimate the mass of the gas disk and to measure molecular abundances. Their observed depletion may be due to condensation of molecules onto dust grains.

Map on the right : Interferometer map of GM Auriga. The thermal emission of the dusty disk at 1.3 mm (radius around 150 AU) is shown in false colors. In contours, the much more extended gaseous disk is seen in the 12CO (2-1) line (radius about 700 AU).