Interstellar extinction

1. Nov 23, 2007

randa177

The presence of interstellar extinction makes stars appear dimmer and appear more “distant” than they truly are. (This is true for individual stars and for clusters of stars). Does dust affect the observed angular size of a star cluster (assuming the distribution of the dust is smooth)? That is, suppose there was a star cluster located 100 pc away. Would adding dust extinction affect its observed angular size?

2. Nov 23, 2007

mgb_phys

No the dust just reduces the apparent brightness, and changes the obserserved colour.