The observed H2O and OH masers are listed in Table 1 (click here). For
each source we report the FC89 name (the 5 presented in Paper I and
reobserved in June 1994 are marked with an 
), the 1950 coordinates of
the H2O maser and the distance from the Sun (from FC89), the IRAS
name of the IRAS-PSC source (if any within 1 arcmin from the
maser position), and the limiting magnitudes achieved in our observations
(see below).
All the sources were observed in J, H and K (
m,
m and 
m respectively) NIR
broad bands using the Las Campanas NIR camera (Persson et al. 1992) equipped with a NICMOS3 256
256 HgCdTe array
detector. The sources were observed in two runs at the 1 m telescope (July
1992) and at the 2.5 m telescope (June 1994). The observational and data
reduction techniques were the same as for the preliminary sample presented
in Paper I. The plate scale on the detector was 0.92
/pix at
the 1 m telescope and 0.35/pix at the 2.5 m.
During both observing
runs the seeing was in the range 
.
The data reduction and analysis were performed using the
IRAF
and ARNICA
(Hunt et al. 1994) software packages.
Photometric calibration was achieved by observing a set
of the UKIRT faint standard stars (Casali & Hawardeen 1992)
each night. The calibration accuracy is in the range 
depending on
the weather conditions. The limiting magnitudes
obtained in each field (3
in a 4 pix aperture) are listed
in Table 1 (click here). Photometry was
performed using the IRAF DAOPHOT package.
The key aspect of this project is the comparison of
the NIR images with sub-arcsec resolution positions of the masers.
Consequently, it is important to perform an accurate astrometric calibration
of the NIR images.
This was performed following the procedure
outlined in Testi 1993 using the Digitized Sky Survey
provided by the Space Telescope Science Institute. We reached an
accuracy better than 1 rms.
(1950)
(1950)