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Astron. Astrophys. 347, 137-150 (1999)

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3. Observations

The photometric observations in the optical region (Johnson UBVRI passbands) were obtained between January 1996 and December 1998 using the 1-meter telescope of the Tien-Shan Observatory (Kazakhstan) equipped with the two-channel photometer-polarimeter of the Pulkovo Observatory (Bergner et al. 1988). These observations are given in Tables 2 and 3. Typical errors of these observations, including those of the transformation from the instrumental to the standard photometric system, do not exceed [FORMULA] for the stars brighter than 13m and are somewhat larger for the fainter objects. The observations with errors exceeding 0[FORMULA]05 are marked with colons. Quasi-simultaneous optical (Cousins UBVRI passbands) and near-IR JHK photometry (and one observation of AS 116 in the L-band) of the southern objects from our sample was obtained at the SAAO using the 0.5-meter and 0.75-meter telescopes respectively during several observing runs in 1997. The errors of the optical photometry are nearly [FORMULA] while those of the IR observations are different and are given in Table 4 along with the results of the SAAO observations.


[TABLE]

Table 2. Photometric observations of other HAEBE candidates at the Tien-Shan Observatory



[TABLE]

Table 3. Photometric observations of MQ Cas at the Tien-Shan Observatory



[TABLE]

Table 4. Optical and near-IR photometry at SAAO


Classification-resolution spectroscopy of the northern objects was obtained between January and November 1998 using the Gray/Miller spectrograph on the 0.8 meter telescope of the Dark Sky Observatory (DSO) of Appalachian State University. These spectra were obtained with a 600 lines mm-1 grating in the first order using a Tektronics 1024 [FORMULA] 1024 thinned, back-illuminated CCD, and have a spectral range of 380-560nm, and a resolving power R of about 1300 (0.36nm/2 pixels). The spectra, except for the two faintest stars (MQ Cas and V1012 Ori) have a signal to noise ratio [FORMULA]. Reductions were carried out using standard IRAF routines. The log of these observations is given in Table 5.


[TABLE]

Table 5. Log of the Classification-resolution Spectroscopic Observations obtained at the Dark Sky Observatory.
Notes:
a) Central moments of the exposures
b) Exposure times in minutes


The spectra of the southern objects were obtained on 1996 March 30 at the Laboratorio Nacional de Astrofisica at Pico dos Dias (Brazil) using the Cassegrain focus of the 1.6-meter telescope, with a [FORMULA] CCD and a 600 lines mm-1 grating with a spectral range of 479-690 nm. The spectra have a signal-to-noise ratio of [FORMULA] 100, and a resolving power R of about 1 000. The data reduction was performed using the IRAF package, in which the standard CCD reduction tasks were used to remove cosmic rays, perform bias subtraction and flat-field the images. Spectral extraction was carried out using the optimal extraction algorithm in the IRAF task apsum , in which pixel values across an order of the spectrum are weighted according to the calculated signal to noise ratio. The spectra were wavelength calibrated using a Thorium/Argon calibration lamp.

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© European Southern Observatory (ESO) 1999

Online publication: June 18, 1999
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