An infrared study of galactic OH/IR stars
II. The “GLMP sample” of red oxygen-rich AGB stars
1
ISO Data Centre / European Space Astronomy Center, Villafranca del Castillo, Apartado de Correos 50727, 28080 Madrid, Spain e-mail: fjimenez@iso.vilspa.esa.es
2
Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: Francisco.Jimenez-Esteban@hs.uni-hamburg.de
3
ISO Data Centre / European Space Astronomy Center, Research and Scientific Support Department of ESA, Villafranca del Castillo, Apartado de Correos 50727, 28080 Madrid, Spain
Received:
19
April
2005
Accepted:
21
July
2005
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 (
). 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 (
) has no counterpart in the 2MASS,
implying extremely high optical depths of their shells. Most of the
sources identified in the 2MASS are faint (
) and are of very
red colour in the near-infrared, as expected. The brightest 2MASS
counterpart (
mag) was found for IRAS 18299–1705. Its blue
colour 
suggests that IRAS 18299–1705 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”.
Key words: stars: AGB and post-AGB
© ESO, 2006