Far-Ultraviolet Extinction in σ Scorpii

  • Theodore P. SnowJr.
  • Donald G. York
Part of the Astrophysics and Space Science Library book series (ASSL, volume 55)


It was found earlier from OAO-2 data (Bless and Savage, 1972) that considerable variability with direction in space is present in both the shape and level (relative to B-V color excess) of the interstellar extinction curve in the far ultraviolet. The star σ Sco was shown to be a case of extremely low UV extinction, but there was some question of whether this could be due to scattered nebular light entering the large entrance slit of the Wisconsin spectrometer aboard OAO-2. We have obtained UV data on σ Sco using Copernicus (OAO-3), which has an entrance slit on the order of 103 times smaller in projected area than that of OAO-2, so that the contribution to the signal from scattered nebular light would be correspondingly smaller. We find very good agreement with the extinction curve of Bless and Savage, confirming the low UV extinction in the line of sight to σ Sco. The curve is extended down to 1000 Å, showing a continued rise towards short wavelengths.


Entrance Slit Comparison Star Color Excess Extinction Curve Reddened Star 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bless, R. C. and Savage, B. D.: 1970, in L. Hourniaux and H. E. Butler (eds.), ‘Ultraviolet Stellar Spectra and Related Ground-Based Observations’, IAU Symp. 36, 28.Google Scholar
  2. Bless, R. C. and Savage, B. D.: 1972, Astrophys. J. 171, 293.CrossRefADSGoogle Scholar
  3. Bohlin, R. C.: 1974, unpublished.Google Scholar
  4. Carruthers, G. R.: 1969, Asirophys. Space Sci. 5, 387.CrossRefADSGoogle Scholar
  5. Rogerson, J. B., Spitzer, L., Drake, J. F., Dressler, K., Jenkins, E. B., Morton, D. C., and York, D. G.: 1973, Astrophys. J. Letters 181, L97.CrossRefADSGoogle Scholar
  6. Savage, B. D.: 1973, in J. M. Greenberg and H. C. van de Hulst (eds.), ‘Interstellar Dust and Related Topics’, IAU Symp. 52, 21.Google Scholar
  7. Stecher, T. P.: 1965, Astrophys. J. 142, 1681.CrossRefADSGoogle Scholar
  8. Stecher, T. P.: 1969, Astrophys. J. Letters 157, L125.CrossRefADSGoogle Scholar
  9. Witt, A. N.: 1973, in J. M. Greenberg and H. C. van de Hulst (eds.), ‘Interstellar Dust and Related Topics’, IAU Symp. 52, 53.Google Scholar
  10. Witt, A. N. and Lillie, C. F.: 1973, Astron. Astrophys. 25, 397.ADSGoogle Scholar
  11. York, D. G., Drake, J. F., Jenkins, E. B., Morton, D. C., Rogerson, J. B., and Spitzer, L.: 1973, Astrophys. J. Letters 182, L1.CrossRefADSGoogle Scholar

Copyright information

© D. Reidel Publishing Company, Dordrecht, Holland 1976

Authors and Affiliations

  • Theodore P. SnowJr.
    • 1
  • Donald G. York
    • 1
  1. 1.Princeton University ObservatoryPrincetonUSA

Personalised recommendations