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Interstellar Grains in Reflection Nebulae

Published online by Cambridge University Press:  08 February 2017

Vladimir Vanysek
Vladimir Vanysek*
Affiliation:
Charles University, Prague, Czechoslovakia

Extract

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Reflection Nebulae are suitable objects for studying the physical nature of interstellar grains. Unfortunately, there exist only a few sufficiently bright objects, the most widely studied being nebula NGC 7023. This nebula has been studied photographically and photoelectrically by many authors, and therefore it is best suited for the verification of some theoretical conclusions. Earlier measurements (refs. 1 to 3) have already shown unambiguously that almost all nebulae exhibit a negative color excess in comparison with the color of the illuminating star. This fact has been verified photoelectrically in reference 4. In the B – V system the average difference between the color of the star and that of a nebula is – 0.2m. These facts have been known for a long time, but the distribution of the color excess in the nebula itself has not been studied very intensively.

Type
Research Article
Information
International Astronomical Union Colloquium , Volume 7: Proper Motions , August 1965 , pp. 123 - 129
Copyright
Copyright © Kluwer Academic Publishers 1965

References

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