Staying ahead of the curve: progress in British variable star astronomy

2017 January 22

Jeremy Shears

Introduction

The BAA Variable Star Section (VSS) is proud to be the world’s longest established organisation for the systematic observation of variable stars, having been established in 1890, within a few days of the formation of the BAA itself. From the outset, the primary aim of the Section has always been to encourage the observation of variable stars and to make the resulting data available for analysis. In the early days, little was known about what a star was made of and it was anticipated that the study of the variables would shed light on the internal constitution of the stars. The new astronomy of astrophysics was dawning, supported by its two new observational techniques: spectroscopy and photography.

Spectroscopy promised to unlock an understanding of the chemical composition of stars, and photography was allowing many more variables to be discovered. The challenge was to enlist a sufficiently large body of astronomers to monitor the stars and derive their lightcurves. By and large this responsibility fell to the vast ranks of amateur astronomers around the world and, in Britain, to the BAA VSS. Other variable star organisations emerged later, notably the American Association of Variable Star Observers (AAVSO), which began in 1911.

In the early years of the VSS when there were only a dozen or so stars on its programme, magnitude estimates were published in the BAA Journal with little or no analysis. However, a rapid growth in observations occurred during the first decades of the twentieth century, encouraged by the dynamic Section Director, Col. Markwick, who extended the programme and drew many new observers into the fold. This gave rise to analyses of the results which were regularly presented in the Journal. The inevitable result was that within a few years the volume of data was too great for it to be practical to publish all observations in the Journal.

The solution was to produce a series of Memoirs, containing all observations and selected lightcurves, each carefully drawn by hand. Eventually the sheer volume of results, and the associated publishing costs, rendered even this approach unaffordable and the final Memoir appeared in microfilm format in 1958, covering the period 1930 to 1934. Few copies of this Memoir were produced and most were deposited at libraries where specialised microfilm readers were available. The consequence was that the information was largely inaccessible to those who might have wanted it…. (continued)

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