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Mt. Hamilton, Cal., July 22,1903.
Professor Dr. Max Wolf, Director,
Astrophysical Observatory, Heidelberg.
Dear Sir:-
The number of variable stars now known is about 1200. They
are among the most interesting bodies in the heavens. Their variations
in brightness have been very carefully studied in a 1 rge number of cases
by able astronomers. In general, such observations do not require expens-
ive or new telescopes.
The successful study of variable star spectra, on the contrary,
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of certain spectral types, that others
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at maximum, etc
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has been my strong desire a take up
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Ceti, Nova Aurigae, Nova Persei, and
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econdary to other programs of work, and
with s
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tensive plans for researches in this Une
which :
personal charge of -- it would assist me
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greatl;
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the study of variable-star spectra is an
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requires powerful and expensive equipment, and the subject is one of
great difficulty. Almost no systematic work on them has been done. If we
of variable-star spectra. Beginning
source;
ield? Is it desirable that increased ro-
ta su< =
i, ;3 Lyrae, Eta Aquilae, Zeta Geminorum, and
!he same types, our knowledge is confined