JOURNAL OF ASTRONOMICAL HISTORY AND HERITAGE ISSN 1440-2807 EDITOR Professor Wayne ORCHISTON (Thailand) ASSOCIATE EDITORS Professor Richard G. STROM (Netherlands) Professor Joseph S. TENN (USA) EDITORIAL BOARD Dr David ANDREWS (England) Professor Rajesh KOCHHAR (India) Dr Alan BATTEN (Canada) Professor LIU Ciyuan (China) Dr Allan CHAPMAN (England) Professor Tsuko NAKAMURA (Japan) Dr Suzanne DÉBARBAT (France) Professor NHA Il-Seong (Korea) Dr Wolfgang DICK (Germany) Professor F. Richard STEPHENSON (England) Dr Steven DICK (USA) Professor Brian WARNER (South Africa) Professor Bambang HIDAYAT (Indonesia) The Journal of Astronomical History and Heritage (JAHH) was founded in 1998, and since 2007 has been produced three times yearly, now in March/April, July/August and November/December. It features review papers, research papers, short communications, correspondence, IAU reports and book reviews. Papers on all aspects of astronomical history are considered, including studies that place the evolution of astronomy in political, economic and cultural contexts. Papers on astronomical heritage may deal with historic telescopes and observatories, conservation projects (including the conversion of historic observatories into museums of astronomy), and historical or industrial archaeological investigations of astronomical sites and buildings. All papers are refereed prior to publication. There are no page charges, and in lieu of reprints authors are sent a pdf or Word camera-ready version of their paper so that they can generate their own reprints on demand. Prospective contributors may download the ‘Guide for Authors’ directly from the internet by going to http://www.narit.or.th/en/files/GuideforAuthors.pdf or request it from Professor Wayne Orchiston ([email protected]). Intending contributors should carefully follow these guidelines when preparing manuscripts. Papers and book reviews should be e-mailed to Professor Orchiston, or posted to him at: National Astronomical Research Institute of Thailand 191 Huay Kaew Road Suthep District Muang Chiang Mai 50200 Thailand The JAHH is now an electronic journal. All content back to Vol. 1 may be downloaded free of charge from either the Journal’s web site at http://www.narit.or.th/en/index.php/jahh or the SAO/NASA Astrophysics Data System site (http://bit.ly/1bMwxBr) and its 12 mirror sites around the world. The electronic version of the journal will continue to be produced three times a year (nominally in March, July and November) and posted on both sites. Those who wish a hard copy may print it out or have it done by their local printers. For this reason a single pdf of each entire issue is available on the site at NARIT. © National Astronomical Research Institute of Thailand. The views and opinions expressed in this Journal are not necessarily those of the Institute, the Editors or the Editorial Board. COVER IMAGE Map showing two confirmed (Wells Creek and Flynn Creek) and two suspected (Dycus and Howell Structures) impact crater scars in Tennessee, USA. Two unusual features of the Dycus Structure – its elongated shape and interior uplift at one end – are reminiscent of the Moon’s Schiller crater (lower image; credit: NASA). They suggest that the Dycus Structure may have been caused by an oblique meteoritic impact. See the paper by Jana Ruth Ford et al. on pages 352–364 of this issue. JOURNAL OF ASTRONOMICAL HISTORY AND HERITAGE ISSN 1440-2807 VOLUME 17 NUMBER 3 NOVEMBER/DECEMBER 2014 CONTENTS Page Papers The Stebbins Galaxy: the origins of interstellar medium studies in the shrinking super-galaxy 240 James Lattis Burmese shadow calculations 258 Lars Gislén and Chris Eade The discovery of quasars and its aftermath 267 K.I. Kellermann John Bolton and the discovery of discrete radio sources 283 Peter Robertson, Wayne Orchiston and Bruce Slee The Aboriginal Australian cosmic landscape. Part 1: The ethnobotany of the skyworld 307 Philip A. Clarke Declinations in the Almagest: accuracy, epoch, and observers 326 John C. Brandt, Peter Zimmer and Patricia B. Jones Harvey Butcher: a passion for astronomical instrumentation 339 Ragbir Bhathal An historical perspective on the suspected meteorite impact sites of Tennessee. 1: The Dycus Structure 352 J.R.H. Ford, Wayne Orchiston and Ron Clendening Index 365 Published by the National Astronomical Research Institute of Thailand, 191 Huay Kaew Road, Suthep DistrIct, Muang, Chiang Mai 50200, Thailand. Journal of Astronomical History and Heritage, 17(3), 240–257 (2014). THE STEBBINS GALAXY: THE ORIGINS OF INTERSTELLAR MEDIUM STUDIES IN THE SHRINKING SUPER-GALAXY James Lattis 475 N. Charter St., Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706, USA. Email: [email protected] Abstract: The development of photoelectric photometry as an observational technique by Joel Stebbins and his colleagues at the University of Wisconsin‘s Washburn Observatory made possible, in the early 1930s, a new approach to the effects, extent, and nature of interstellar matter. In a series of papers published between 1933 and 1936, Stebbins showed that the Shapley galaxy was too large by at least a factor of two and that the size of the Andromeda Galaxy had been significantly underestimated, thus considerably reducing the apparent discrepancy between the two neighboring galaxies. The outcome was not simply a recalibration of the Shapley model, but rather the replacement of the incongruously large and transparent super-galaxy by the modern concept of the Milky Way: a galaxy of size comparable to other spiral galaxies and, like them, containing significant quantities of interstellar dust and gas. This paper explores the role of Stebbins and his colleagues and their applications of photoelectric photometry in formulating the modern concept of our Milky Way galaxy. Keywords: Stebbins, Shapley, interstellar matter, photometry, galaxies. 1 PRELUDE from such neighboring objects as the Andro- meda Nebula, as it was then called. The struc- Quotation from Elizabeth Huffer (wife of C. Morse ture, composition, and dynamics of a unique Huffer): There was one time I can remember ‗super-galaxy‘ as set out by Shapley would be Stebbins coming in saying “We shrunk the uni- very different from the throng of negligible wisps verse!” He had found out these obscuring clouds —the spiral nebulae and globular clusters— and that people thought the stars were so much swarming about it. General accounts mention, further away and it was because they were often vaguely and in passive voice, that Shap- going through this obscuring material and they ley‘s dimensions needed correction. The nature were much closer than they thought they were. of the ‗corrections‘ to the Shapley Galaxy are And he was absolutely jubilant to think that he rarely spelled out. In particular, who made these had made a discovery. corrections, and how? As we see above, Eliz- C. Morse Huffer (long time colleague of Steb- abeth Huffer thought that Joel Stebbins (Figure bins): Yes, he and Shapley were quite rivals. 1) did it. Stebbins‘s triumphant ―We shrunk the Shapley had got the length of the galaxy as universe!‖ (as reported by Elizabeth Huffer) 200,000 light years and Stebbins got it at hints at the cosmological implications of the 100,000. work, which not only corrected Shapley‘s con- Elizabeth Huffer: And, of course, Stebbins was clusions, but opened the way to a view of a Uni- right … he was absolutely jubilant. You would verse filled with countless galaxies comparable go into that observatory and there was just a to our own. Getting the dimensions of the Gal- feeling of exhilaration. He had made a axy correct involved the first explorations of the milestone and he knew it. (Huffer, 1977). interstellar medium with the new technology of photoelectric photometry. To understand the 2 INTRODUCTION significance of the work of Stebbins and the other Wisconsin astronomers, we need first to The discovery that the Sun is nowhere near the see the stage that Shapley had set. center of our Milky Way galaxy constitutes one of the most significant insights of 20th-century 3 CONSTRUCTING THE SHAPLEY GALAXY astronomy. It is one among several fundamental facts that define what we now mean by the very As early as 1917, Harlow Shapley, then working word ―galaxy,‖ a term whose modern meaning at Mt. Wilson Observatory, recognized the sig- only began to emerge in the 1920s. Harlow nificance of the apparent asymmetry of the Shapley (1885–1972), referred to in the quota- distribution of globular clusters for determining tion above, opened this new direction in the the location of our Solar System relative to the study of our Galaxy with his survey of globular rest of the Galaxy. The distinct asymmetry of clusters and construction of their relative dis- the distribution of globular clusters as seen in tribution in three dimensions. But the Shapley the sky had been established by others, such as Galaxy, as formulated by him, was a factor of Karl P.T. Bohlin (1860–1939), P.J. Melotte two or three times too large, was transparent (1880–1961), and Arthur R. Hinks (1873–1945) (effectively free of gas and dust), and was (Jeans, 1929: 25; Smith, 2006: 320–321), but asserted by him to be fundamentally different Shapley was the first to obtain distances to the Page 240 James Lattis The Stebbins Galaxy globular clusters. The result of those measure- constant and inferred the distances from their ments provided a three-dimensional distribution apparent diameters, calibrated from the cluster of the globular clusters from which he drew bold distances known from the previous arguments. conclusions about the size and structure of our In this way Shapley established a ‗distance Galaxy. Assuming that the globular clusters ladder‘, which gave absolute distances to the form a symmetric halo around the center of the globular clusters. Combining the distances with Galaxy, their apparent distribution in our sky the known positions in the sky allowed him to and, critically, their distances tell us that the Sun construct the three-dimensional distribution of is far from that center, which must lie roughly in the system of globular clusters and gauge the the direction of the constellation Sagittarius.