Paul W. Merrill

Paul Willard Merrill (August 15, 1887 – July 19, 1961) was an American astronomer whose specialty was spectroscopy.<ref>Template:Cite journal</ref> He was the first person to define S-type stars, in 1922.<ref name="merrill22">Template:Cite journal</ref>

Career

Merrill received his Ph.D. at the University of California (now UC Berkeley) in 1913. He spent the bulk of his career at Mount Wilson Observatory, from which he retired in 1952. He studied unusual stars, particularly long-period variable stars, using spectroscopy. He also studied the interstellar medium, including diffuse interstellar bands. Shortly before he retired, he succeeded in detecting technetium in the variable star R Andromedae and other red variables. Since technetium has no stable isotopes, it must have been produced recently in any star in which it is found, and this is direct evidence of the s-process of nucleosynthesis.<ref>Template:Cite journal</ref><ref>Template:Cite web</ref>

Honors

Awards and honors

• Member of the United States National Academy of Sciences (1929)<ref>Template:Cite web</ref>
• Member of the American Philosophical Society (1939)<ref>Template:Cite web</ref>
• Henry Draper Medal of the National Academy of Sciences (1945)<ref name="Draper">Template:Cite web</ref>
• Bruce Medal of the Astronomical Society of the Pacific (1946)<ref>Template:Cite web</ref>
• Henry Norris Russell Lectureship of the American Astronomical Society (1955)<ref name=AAS>Template:Cite web</ref>
• Fellow of the American Academy of Arts and Sciences (1958)<ref name=AAAS>Template:Cite web</ref>

Named after him

• Merrill (crater) on the Moon

External links

• Template:Biographical Memoirs

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