Present Status of Spectral Classification in the Conventional Wavelength Range with Emphasis Upon Early-Type Stars

  • C. Jaschek
Part of the International Astronomical Union / Union Astronomique Internationale book series (IAUH, volume 4-2)


A spectral classification system is a morphological device for arranging in order a finite series of observations of individual objects. One has thus three elements: an “order”, i.e. an abstract discontinuous scheme, a series of objects and a certain type of observation (spectrogram) that is performed on all objects of the sample. The “order” is in principle arbitrary; one could think for instance of an order based on richness of lines, or on the presence of hydrogen lines, etc. However such an idealization is clearly simplistic, because it would imply that the classifier is completely unaware of theory — but he is not, if for no other reason than simply that he would never get his PhD. Thus one should add the constraint that the scheme one adopts be physically sound.


Spectral Type Stellar Atmosphere Spectral Classification Luminosity Class Peculiarity Group 
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. Morel et al. (1976) IAU Symp, no. 72, in press.Google Scholar
  2. Jaschek C. (1976) IAU Symp, no. 72, in press.Google Scholar
  3. Morel et al, (1976) IAU Symp, no. 72, in press.Google Scholar
  4. Morgan W.W. and Keenan P. (1973) Ann. Rev. of Astr. and Astroph. 11, 29.ADSCrossRefGoogle Scholar
  5. Walborn N.R. (1972) Ap. J. Suppl. 23, 257.ADSCrossRefGoogle Scholar

Copyright information

© IAU 1977

Authors and Affiliations

  • C. Jaschek
    • 1
  1. 1.Observatoire de StrasbourgFrance

Personalised recommendations