اعتتام المادة ما بين النجوم بواسطة حبيبات البكتريا

The aim of this work is to study the extinction caused by interstellar Dust in different regions like HD 177989 , HD 179407 , HD 172140 , HD 178487 and the average of it in our galaxy through out the comparison between observational data and the theoretical bacterial model . The biological material put the basic thump stamp on the component’s of the interstellar grains in these regions in addition to the graphite and dielectric sphere.