The UV extinction laws in two very young clusters, NGC 6530 in the galaxy and NGC 2100 in the LMC

摘要

The UV extinction for a number of O and B stars in the galactic cluster NGC 6530 was studied along with the extinction law for several stars in the LMC cluster NGC 2100. Distinct differences were found for different stars in the same cluster. In NGC 6530 a correlation of the extinction law with T sub EFF or with position in the cluster was observed. In NGC 2100 the 2200 A absorption appears to be much stronger in the center of the cluster. The interstellar gas line absorption for the stars in NGC 6530 was also studied. No correlation with the variations in the UV extinction law was found so far.