Published online by Cambridge University Press: 25 May 2016
Table 1 summarizes results of programs to determine distances and metallicities of high-velocity clouds (HVCs, see Wakker 1991, IAU Symp 144, 27 for a general review). Reliable absorption is reported for one stellar probe (BD+38 2182), giving a distance D<5kpc for complex M. Other results are controversial (BT Dra), uncertain(HD 135485) or atypical (4 Lac). Non-detections reported by e.g. Lilienthal et al. (1990, A&A 240, 287), Danly et al. (1992, ApJS 81, 125) and de Boer et al. (1994, A&A 286, 925), yield lower limits up to 2 kpc for complexes A, C and M. Absorption by heavy elements in HVCs is reported for twelve extra-galactic probes. All absorptions reported in HVCs with |v LSR| > 90km/s are given in the table (abundances are from low-resolution HI data and thus uncertain).