Question: The BFH paper, named after the initials of the authors of the paper, a landmark paper of stellar physics published in "Reviews of Modern Physics" in which year?
Context: The term heliophysics means "physics of the Sun" (the prefix "helio", from Attic Greek "hḗlios", means Sun), and appears to have been used only in that sense until quite recently.  In the early times, heliophysics was concerned principally with the superficial layers of the star, and was synonymous with what is now more commonly called "solar physics".  Usage was extended explicitly in 1981 to its literal meaning, denoting the physics of the entire Sun: from center to corona, and has been used in that sense since.  As such it was a direct translation from the French "héliophysique", which had been introduced to provide a distinction from "physique solaire" (solar physics).  It thus became a subdiscipline of heliology.  Early in the 21st century the meaning of the term was extended by Dr George Siscoe of Boston University to include the physics of the heliosphere (the space around the Sun beyond the corona, in principle out to the shock where the solar wind encounters the interstellar medium, but excluding the planets and other condensed bodies), although Siscoe's view of the discipline appears not to contain most of the true realm of endeavour.  The term was adopted in Siscoe's restricted sense by the NASA Science Mission Directorate to denote the study of the heliosphere and the objects that interact with it—most notably planetary atmospheres and magnetospheres, the solar corona, and the interstellar medium.  Heliophysics combines several other disciplines, including solar physics, and stellar physics in general, and also several branches of nuclear physics, plasma physics, space physics and magnetospheric physics.  Solar wind interaction with magnetized planets, Solar wind propagation, Solar activity effects on planetary magnetospheres.  Solar magnetic field configuration from the Sun to the Heliopause.  The recent extension of heliophysics is closely tied to the study of space weather and the phenomena that affect it, and consequently to climatology.  To quote Siscoe from a recent conference presentation: The cornerstone of the Estonian cosmological research is the Tartu Observatory which was founded in 1812.  The observatory itself has a long tradition of studying galaxies and theoretically modeling the structure of the universe and its formation.  Till today this facility is Estonia’s main research centre for astronomy and atmospheric physics, with fundamental research focusing on physics of galaxies, stellar physics and remote sensing of the Earth’s atmosphere and ground surface.  The observatory has also played a vital role in catapulting the career of Jaan Einasto, one of the most famous and eminent Estonian astrophysicists and one of the discoverers of "Dark Matter" and of the cellular structure of the Universe. Modern Physics Letters A (MPLA) is the first in a series of journals published by World Scientific under the "Modern Physics Letters" moniker.  It covers specifically papers and research on gravitation, cosmology, nuclear physics, and particles and fields. Neutron capture nucleosynthesis describes two nucleosynthesis pathways: the r-process and the s-process, for "rapid" and "slow" neutron captures, respectively.  R-process describes neutron capture in a region of high neutron flux, such as during supernova nucleosynthesis after core-collapse, and yields neutron-rich nuclides.  S-process describes neutron capture that is slow relative to the rate of beta decay, as for stellar nucleosynthesis in some stars, and yields nuclei with stable nuclear shells.  Each process is responsible for roughly half of the observed abundances of elements heavier than iron.  The importance of neutron capture to the observed abundance of the chemical elements was first described in 1957 in the BFH paper. Reviews of Modern Physics is a quarterly peer-reviewed scientific journal published by the American Physical Society.  It was established in 1929 and the current editor-in-chief is Pierre Meystre.  The journal publishes review articles, usually by established researchers, on all aspects of physics and related fields.  The reviews are usually accessible to non-specialists and serve as introductory material to graduate students, which survey recent work, discuss key problems to be solved and provide perspectives toward the end.  RMP is arguably one of the most, if not the most, prestigious, authoritative and highly impacting journals in the field of physics.  Its most recent impact factor for 2015 is 33.177 with a 5-year impact factor of 46.681. Solar physics is the branch of astrophysics that specializes in the study of the Sun.  It deals with detailed measurements that are possible only for our closest star.  It intersects with many disciplines of pure physics, astrophysics, and computer science, including fluid dynamics, plasma physics including magnetohydrodynamics, seismology, particle physics, atomic physics, nuclear physics, stellar evolution, space physics, spectroscopy, radiative transfer, applied optics, signal processing, computer vision, computational physics, stellar physics and solar astronomy. John Allen "Jack" Eddy (March 25, 1931 – June 10, 2009) was an American astronomer who published professionally under the name John A. Eddy but much of the content referencing him can be found under his nickname Jack which he preferred to use.  In 1976 Dr. Eddy published a landmark paper in Science titled "The Maunder Minimum" where, using the Nineteenth Century works of Edward W. Maunder and Gustav Spörer, he identified a 70-year period from 1645 to 1715 as a time when solar activity all but stopped.  In making the case for the anomaly, he gathered and interpreted data from a wide variety of sources, including first-hand accounts from extant historical observations of the Sun going back to the telescopic observations of Galileo and other contemporary scientists of the 17th and early 18th centuries; from historical reports of the aurora borealis observed in past centuries in Europe and the New World; from visual observations of sunspots seen with the unaided eye at sunrise and sunset in dynastic records from the Orient; from existing descriptions of the eclipsed Sun; and from measurements of carbon-14 in dated tree-rings.  In the last of these, which can be used as a proxy indicator of solar activity, he found evidence of other similar periods of solar quiescence in the distant past, the most recent an even longer 90-year span, from about 1460 until 1550, which he named the Spörer Minimum.  Both the Maunder and Spörer minima fell during the coldest parts of the Little Ice Age, which suggested a meaningful connection between the longer term behavior of the Sun and of the Earth’s mean surface temperature.  In advancing the theory that the Sun is a variable star Eddy observed: "It has long been thought that the Sun is a constant star of regular and repeatable behavior.  Measurements of the radiative output, or solar constant, seem to justify the first assumption, and the record of periodicity in sunspot numbers is taken as evidence of the second.  Both records, however, sample only the most recent history of the Sun." Eleanor Margaret Burbidge ("née" Peachey), FRS (born August 12, 1919 in Davenport) is a British-born American astrophysicist, noted for original research and holding many administrative posts, including Director of the Royal Greenwich Observatory. Letters in Mathematical Physics is a peer-reviewed scientific journal in mathematical physics published by Springer Science+Business Media.  It publishes letters and longer research articles, occasionally also articles containing topical reviews.  It is essentially a platform for the rapid dissemination of short contributions in the field of mathematical physics.  In addition, the journal publishes contributions to modern mathematics in fields which have a potential physical application, and developments in theoretical physics which have potential mathematical impact.  The editors are Volker Bach, Edward Frenkel, Maxim Kontsevich, Dirk Kreimer, Nikita Nekrasov, Massimo Porrati, and Daniel Sternheimer. The BFH paper, named after the initials of the authors of the paper, Margaret Burbidge, Geoffrey Burbidge, William Fowler, and Fred Hoyle, is a landmark paper of stellar physics published in "Reviews of Modern Physics" in 1957.  The formal title of the paper is "Synthesis of the Elements in Stars", but the article is generally referred to only as "BFH".
Answer: 1957