Astron. Astrophys. 363, 1040-1050 (2000)

2. Observational data

In Table 1 and Table 2 we summarize the follow-up spectroscopy and give coordinates, magnitudes, names from other surveys, and spectral types, if already existing, for the observed helium-rich white dwarfs. The instruments used for spectroscopy were the ESO Faint Object Spectrograph and Camera (EFOSC), the Danish Faint Object Spectrograph and Camera (DFOSC), and the Boller & Chivens Spectrograph (B&C). A # in Table 1 refers to ESO numbering of grisms, for which details can be found in the according telescope manuals. In general a spectral range between about 3800Å and 7000Å up to 9000Å is covered with resolutions between about 100 to 500 Å /mm. The coordinates have been derived from the Digitized Sky Survey I (DSS-I). Therefore, finding charts can easily be obtained from the online DSS-I. Magnitudes are given as magnitude, which is defined by the sensitivity curve of the hyper-sensitized Kodak IIIa-J emulsion combined with the filter function of a Schott BG395 filter. is roughly equal to B for objects around and accurate to better than   for all sample stars.

Table 1. Journal of observations

Table 2. Coordinates, magnitudes, cross-references and spectral types, if already existing, for the observed objects. Cross-references were taken from the Simbad database and McCook & Sion (1999). Most of the EC objects are listed in Kilkenny et al. (1997). Details of individual observing campaigns can be found in Table 1. The survey fields, given in column "field", are ESO/SERC atlas fields. The magnitudes are accurate to better than .
Notes:
a) classified as magnetic WD without detectable polarization in McCook & Sion (1999), Magnetic white dwarf with a polar field strength of 176 MG (Reimers et al.1996).
b) mistakenly identified as PHL1201 in Lamontagne et al. (2000)
c)coincidenceswithP H Lobjects(P H L3345; P H L1477; P H L166; P H L363)havebeenrejectedusingf indingchartsprovidedbyE:  C havira
d) finding chart from Jaidee & Lyngå (1969)

The spectra of all DB white dwarfs are depicted in Figs. 1-3. The spectra of DBA and DBAZ white dwarfs can be found in Fig. 4 and Fig. 5, respectively, and the spectra of the DZ, DQ, and DC white dwarfs are summarized in Fig. 6.

Fig. 1. DB white dwarfs

Fig. 2. DB white dwarfs (continued)

Fig. 3. DB white dwarfs (continued)

Fig. 4. DBA white dwarfs

Fig. 5. DBAZ white dwarfs

Fig. 6. DZ, DQ, and DC white dwarfs

© European Southern Observatory (ESO) 2000

Online publication: December 5, 2000
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