This review summarises the invited presentation I gave on the Milky Way disc.
The idea underneath was to touch those topics that can be considered hot
nowadays in the Galactic disk research: the reality of the thick disk, the
spiral structure of the Milky Way, and the properties of the outer Galactic
disk. A lot of work has been done in recent years on these topics, but a
coherent and clear picture is still missing. Detailed studies with high quality
spectroscopic data seem to support a dual Galactic disk, with a clear
separation into a thin and a thick component. Much confusion and very
discrepant ideas still exist concerning the spiral structure of the Milky Way.
Our location in the disk makes it impossible to observe it, and we can only
infer it. This process of inference is still far from being mature, and depends
a lot on the selected tracers, the adopted models and their limitations, which
in many cases are neither properly accounted for, nor pondered enough. Finally,
there are very different opinions on the size (scale length, truncation radius)
of the Galactic disk, and on the interpretation of the observed outer disk
stellar populations in terms either of external entities (Monoceros,
Triangulus-Andromeda, Canis Major), or as manifestations of genuine disk
properties (e.g., warp and flare).Comment: 7 pages, 9 figures. Full text in English. To be published in the 57
Bulletin of the Argentinian Association of Astronomy (BAAA 57
