2006A&A...446..773J

We present optical and near-infrared finding charts taken from the DSS and 2MASS surveys of 94 IRAS sources selected from the GLMP catalogue, and accurate astrometry (≃0.2'') for most of them. Selection criteria were very red IRAS colours representative for OH/IR stars with optically thick circumstellar shells and the presence of variability according to the IRAS variability index (VAR>50). The main photometric properties of the stars in this ``GLMP sample'' are presented, discussed and compared with the correspondent properties of the ``Arecibo sample'' of OH/IR stars studied nearlier. We find that 37% of the sample (N=34) has no counterpart in the 2MASS, implying extremely high optical depths of their shells. Most of the sources identified in the 2MASS are faint (K>8) and are of very red colour in the near-infrared, as expected. The brightest 2MASS counterpart (K=5.3mag) was found for IRAS18299-1705. Its blue colour H-K=1.3 suggests that IRAS18299-1705 is a post-AGB star. Few GLMP sources have faint but relatively blue counterparts. They might be misidentifed field stars or stars that recently experienced a drop of their mass loss rates. The ``GLMP sample'' in general is made of oxygen-rich AGB stars, which are highly obscured by their circumstellar shells. They belong to the same population as the reddest OH/IR stars in the ``Arecibo sample''.