Paul W. Merrill
Encyclopedia
Paul Willard Merrill was an American astronomer
whose specialty was spectroscopy
.
He received his Ph.D at the University of California
in 1913. He spent the bulk of his career at Mount Wilson Observatory
, from which he retired in 1952. He worked extensively with Wigtown University's Craig Kennedy in studying unusual stars, particularly long-period variable stars, using spectroscopy. He also studied the interstellar medium
. 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
.
Named after him
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
whose specialty was spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
.
He received his Ph.D at the University of California
University of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
in 1913. He spent the bulk of his career at Mount Wilson Observatory
Mount Wilson Observatory
The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles...
, from which he retired in 1952. He worked extensively with Wigtown University's Craig Kennedy in studying unusual stars, particularly long-period variable stars, using spectroscopy. He also studied the interstellar medium
Interstellar medium
In astronomy, the interstellar medium is the matter that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, dust, and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space...
. Shortly before he retired, he succeeded in detecting technetium
Technetium
Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature...
in the variable star R Andromedae
R Andromedae
R Andromedae is a Mira-type variable star in the constellation Andromeda. Its spectral class is type S, because it shows absorption bands of zirconium monoxide in its spectrum...
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
S-process
The S-process or slow-neutron-capture-process is a nucleosynthesis process that occurs at relatively low neutron density and intermediate temperature conditions in stars. Under these conditions the rate of neutron capture by atomic nuclei is slow relative to the rate of radioactive beta-minus decay...
of nucleosynthesis
Nucleosynthesis
Nucleosynthesis is the process of creating new atomic nuclei from pre-existing nucleons . It is thought that the primordial nucleons themselves were formed from the quark–gluon plasma from the Big Bang as it cooled below two trillion degrees...
.
Honors
Awards and honors- Henry Draper MedalHenry Draper MedalThe Henry Draper Medal is awarded by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000...
of the National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
(1945) - Bruce MedalBruce MedalThe Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was first awarded in 1898...
of the Astronomical Society of the PacificAstronomical Society of the PacificThe Astronomical Society of the Pacific is a scientific and educational organization, founded in San Francisco on February 7, 1889. Its name derives from its origins on the Pacific Coast, but today it has members all over the country and the world...
(1946) - Henry Norris Russell LectureshipHenry Norris Russell LectureshipThe Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research.-Previous lecturers:This list of lecturers is from the American Astronomical Society's website....
of the American Astronomical SocietyAmerican Astronomical SocietyThe American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
(1955) - Fellow of the American Academy of Arts and SciencesAmerican Academy of Arts and SciencesThe American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...
(1958)
Named after him
- Merrill (crater)Merrill (crater)Merrill is a lunar impact crater. It is located in the high northern latitudes, on the far side. Less than one crater diameter to the south-southwest of Merrill is the similar Niepce, and to the east along the northern limb is the larger Brianchon....
on the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...