Optical and IR observations were performed at La Silla, Asiago and Loiano Observatories in 1984-1985, 1989 and 1996 respectively, at different telescopes.
CCD UBV photometric observations were carried out on January 17, 1996 at
Loiano 1.52 m telescope with the BFOSC (Bologna Faint Object Spectrograph and
Camera) used in camera mode.
(V = 8.96) and 
(V = 9.28)
were used as standard stars.
The data were reduced using specific photometric routines of the ESO MIDAS software.
Low, medium and high-dispersion spectroscopy was performed using different telescopes from April 1984 to January 1996. The journal of observations is presented in Table 1 (click here).
In April 1984 and March-April 1985 we obtained 33 low dispersion spectra at the ESO 1.52 m telescope equipped with a Boller & Chivens spectrograph + IDS (Image Dissector Scanner) detector with different reciprocal dispersions. 22 spectra were secured in order to detect variability on timescales of seconds and minutes. More recently, in January 1996, we obtained a spectrum at the Loiano 1.52 m telescope equipped with the BFOSC + CCD detector.
IDS spectra were calibrated in flux and wavelength using the IHAP software. Subsequently they were analyzed using the MIDAS software both for continuum normalization and for the determination of spectral line parameters. The BFOSC spectrum was wavelength-calibrated, normalized to the continuum and analyzed by MIDAS software.
In March and April 1985 five high-dispersion spectra were obtained at the ESO 1.4 m CAT (Coudé Auxiliary Telescope) telescope with CES (Coudé Echelle Spectrometer) spectrograph equipped with a Reticon detector and one high-dispersion spectrum was secured at the ESO 3.6 m telescope with CASPEC (Echelle Cassegrain Spectrograph) spectrograph equipped with a CCD detector.
Exposures ranging from 1.5 to 2.5 hours were employed for CES spectra, while a 15 minute exposure was used for CASPEC spectrum. The spectra were reduced with IHAP and/or MIDAS software packages.
In October 1989 three medium-dispersion spectra were secured at the 1.82 m Asiago telescope with RES (Reosc Echelle Spectrograph) spectrograph equipped with a CCD detector. Exposures ranging from 30 minutes to 50 minutes were employed.
The RES echelle orders were straightened through dedicated software developed at the Astronomical Observatory of Capodimonte; in a further stage the spectra were calibrated in wavelength, normalized to the continuum and analyzed using the MIDAS software.
In January 1996 we obtained one medium-dispersion spectrum with an echelle grism at the BFOSC spectrograph. The spectrum was reduced and analyzed as RES spectra.
All spectra were reduced to heliocentric velocities.
Infrared photometric observations were carried out at the ESO 1 m telescope in April 1984 and March-April 1985. We used an InSb photometer detector with JHKLM filters. The integration times ranged from 45 seconds to 2 minutes depending on the filters and the selected signal to noise ratio. We used the following standard stars, extracted from the specific ESO Photometric Catalogue: HR 5132, HR 6748, HR 4167, HR 3314, HR 2970, HR 5824, HR 2845, HR 3842, HR 7120, HR 6736, HR 4695. JHKLM magnitudes were corrected for atmospheric extinction using the average ESO extinction coefficients.
Narrow band spectrophotometric observations were performed in the
same period at the ESO 1 m telescope + InSb photometer + CVFs in order to
give the energy distribution in the IR region up to 5 
m. The spectral
resolving power was 70. The integration time for each filter was
30-45 seconds. In order to obtain the measurements in the full range for
each CVF, 5-30 minutes were required. HR 2970, HR 4013, HR 5966 and HR
6748, extracted from the specific ESO Photometric Catalogue,
were used as standard stars. The journal of observations
is presented in Table 2 (click here).
The IR observations were almost simultaneous with the spectroscopic observations.
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