New Astronomy, 7, 117-123 (2002/May-0)
The relation between far-UV and visible extinctions.
Abstract (from CDS):
For directions of sufficient reddening (E(B-V)≳0.25), there is a simple relation between the slope of the extinction curve in the far-UV and E(B-V). Regardless of direction, the far-UV extinction curve is proportional to 1/λn e-2E(B-V)/λ (λ in µm, n=4), in accordance with the idea that reddened stars spectra are contaminated by scattered light (Zagury, 2001b). This relation is not compatible with the standard theory of extinction which states that far-UV and visible extinctions are due to different classes of particle. In that model the two (far-UV and visible) extinctions vary thus independently according to the proportion of each type of particle. In preceding papers I have shown that the standard theory cannot explain UV observations of nebulae, and is contradicted by the UV spectra of stars with very low reddening: for how long shall the standard theory be considered as the interpretation of the extinction curve?