News | Published:

Astrophysical Notes



    STARS WITH SPECTRA OF THE THIRD TYPE.—Prof. Dunér has published an important catalogue of stars having banded spectra. Following Prof. Vogel's classification he prefers to regard the spectra with bands fading away towards the violet as a subdivision of the same type as those in which the bands fade away towards the red, rather than, with Secchi, to make them into a separate class. Duner's type III. a, therefore, corresponds to Secchi's third type and his III. b to Secchi's fourth type. Prof. Dunér's purpose in forming this catalogue is to supply the means for future observers to detect changes in these spectra should any such occur, for, as he points out, these stars are probably in a very advanced state of development, and we may therefore, perhaps, hope to discover some day changes in their spectra which, carefully studied, may lead to important results as to the nature of suns. They are the more interesting, also, because variable stars of long period usually belong to this class.

    Rights and permissions

    To obtain permission to re-use content from this article visit RightsLink.

    About this article


    By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.