Joint meeting of the American Astronomical Society and its Historical Astronomy Division, Laboratory Astrophysics Division, and Solar Physics Division. All sessions and meetings are in the Westin Copley Place.
Session #203: Tuesday, 3 June 2014, 10:00–11:30 a.m., Staffordshire Room
Session Chair: Jay M. Pasachoff, Williams College
Description: This special session is part of HAD's effort to spread interest in historical astronomy to those attending the AAS divisional meetings (also DPS in Fall 2013 and 2014), most of whom do not attend the January main AAS meeting at which HAD traditionally has its sessions.
Jay Pasachoff, Session Organizer
10:00 1. The Discovery of the Solar 5-minute Oscillations and the Supergranulation
Robert W. Noyes, Harvard-Smithsonian Center for Astrophysics.
The summer of 1960 marked the discovery, from the Mt. Wilson 60-foot solar tower telescope, of both the solar 5-minute oscillation and the supergranulation. We review the history of how, starting in 1955, Robert Leighton at Caltech carried out studies of the sun at high resolution from the Mt. Wilson 60-foot solar tower telescope. In 1958 he developed a method to map the spatial distribution of solar magnetic fields by photographically subtracting pairs of spectroheliograph images differing only in the sign of their Zeeman-effect sensitivity to longitudinal magnetic fields, and showed for the first time that photospheric magnetic fields trace out the heating of the overlying chromosphere as revealed by the pattern of the Ca II emission network. Leighton then developed a variation of the technique to measure velocity fields and their spatial and temporal variation, and in the summer of 1960 he and his students made a series of discoveries that changed the face of solar physics. One of these was the discovery that the velocity field of the sun exhibits a very strong quasi-periodic vertical oscillation with a period of about 5 minutes; this discovery represents the dawn of helioseismology, which over the past 50 years has grown to embrace research lines in solar and stellar astrophysics that were unimaginable at the time. A parallel discovery made by Leighton and his students during that same summer was the 'large cells', later to be termed the supergranulation, which show a complex pattern of flow fields, evidently produced by large-scale convective motions that are still not well-understood, but which create the magnetic network and hence the pattern of heating in the overlying chromosphere.
10:12 2. Origin of the Wang-Sheeley-Arge Solar Wind Model
Neil R. Sheeley, U.S. Naval Research Laboratory.
A correlation between solar wind speed at Earth and the amount of field line expansion in the corona was verified in 1989 using 22 years of solar and interplanetary observations. This talk will trace the history of this discovery from its birth 15 years earlier in the Skylab era to its current use as a space weather forecasting technique. This research was supported by NASA and ONR.
10:24 3. Lockheed Solar Observatory and the Discovery of Moreton-Ramsey Waves
Theodore D. Tarbell, Lockheed Martin Solar and Astrophysics Laboratory.
Moreton Waves are high-speed disturbances seen traveling away from large solar flares in H-alpha movies of the solar chromosphere. They were discovered by the observer Harry Ramsey in the late 1950s, and then published and publicized by the director Gail Moreton, both of the Lockheed Solar Observatory in the Hollywood Hills of Southern California. These efforts established the scientific reputation and secured continuing funding of the observatory, whose present-day successor is the Lockheed Martin Solar and Astrophysics Lab in Palo Alto. Moreton waves are rare, and there was limited interest in them until the EIT instrument on SOHO began seeing large numbers of similar waves in the corona in the late 1990s. The exact relation between the two observations is still a research topic today. This talk will describe some of the history of the observatory and the discovery and early interpretation of the waves.
10:36 4. On the Naming and Discovery of the Solar Chromosphere
Kevin P. Reardon, National Solar Observatory.
The chromosphere was discovered by Lockyer and Janssen in 1868, and named by Lockyer. It is often stated that his motivation for associating this region of the solar atmosphere with 'color' was because of its bright red appearance at eclipses due to the predominance of H-alpha. However, Lockyer had never seen a total solar eclipse at the time he gave the name and does not appear to have provided this justification himself. It is more likely that the 'color' refers to the plethora of different colored emission lines he saw and identified with his spectrograph. I also discuss the Padre Angelo Secchi's observation of the 1860 eclipse in Spain, His accurate description of the chromosphere as a complete, theretofore unseen layer enveloping the Sun predates Lockyer and Janssen by eight years.
10:48 5. Constructing 'Black Sun': the Documentary Film of the 2012 Eclipses
Jarita Holbrook, University of the Western Cape.
2012 offered an opportunity that was not to be missed: two solar eclipses. Drs. Alphonse Sterling and Hakeem Oluseyi began doing collaborative research during total solar eclipses in 2006 in Ghana. Since then they have continued to do eclipse observation when funds and whether permitted. As a filmmaker, the opportunity to film Sterling and Oluseyi during the 2012 eclipses in Tokyo and Cairns fulfilled the goal of showing the excitement of time-sensitive research, the lives of astrophysicists, and diversity within the astronomy community. As an astrophysicist who did not specialize in solar astrophysics, it was an opportunity for me both to learn and to solidify for the audience what we know about the sun and the importance of eclipse observation. Clips of the film will be included.
11:00 6. Howard Russell Butler's Oil Paintings of Solar Eclipses and Prominences
Jay M. Pasachoff, Williams College and Roberta J.M. Olson, New-York Historical Society.
Howard Russell Butler (1856-1934) was invited to join the US Naval Observatory expedition to the total solar eclipse of 1918 because of his ability to paint astronomical phenomena based on quickly-made notes about spatial and color details. His giant triptych of the total eclipses of 1918, 1923, and 1925 was proposed for a never-built astronomical center at the American Museum of Natural History and wound up at their Hayden Planetarium when it was constructed in the mid-1930s. Half-size versions are installed at the Fels Planetarium at the Franklin Institute in Philadelphia and at the Firestone Library of Princeton University, whose newly conserved canvases were recently hung; the Buffalo Museum of Science has another half-size version in storage. We discuss not only the eclipse triptychs but also the series of large oil paintings he made of solar prominences (in storage at the American Museum of Natural History) and of his 1932-eclipse and other relevant works. JMP was supported for this work in part by Division III Discretionary Funds and the Brandi Fund of Williams College. His current eclipse research is supported by grants AGS-1047726 from the Solar Research Program of the Atmospheric and Geospace Sciences Division of NSF and 9327-13 from the Committee for Research and Exploration of the National Geographic Society.
11:12 7. Exceptional Portable Sundials at Harvard
Sara Schechner, Harvard University.
The Collection of Historical Scientific Instruments at Harvard University has the largest assemblage of sundials in North America. The dials date from the 16th to the 19th centuries, and most are designed to be carried in one's pocket or put on a window sill. They take advantage of the sun's changing altitude, azimuth, hour angle, or a combination of the foregoing in order to find the time. Many are also usable at a wide range of latitudes, and therefore are suitable tools for travelers. Fashioned of wood, paper, ivory, brass, and silver, the sundials combine mathematical projections of the sun’s apparent motion with artistry, fashion, and exquisite craftsmanship. This paper will explore the wide variety of sundials and what they tell us about the people who made and used them.
Tuesday, 3 June 2014, 12:30 p.m., Harvard University
Past HAD Chair Dr. Schechner will conduct a tour of the Harvard Collection of Historical Scientific Instruments, which she heads, at 12:30 p.m. Those wishing to participate will join in traveling by public transportation at trivial cost to Harvard Square immediately after the close of the morning session. Lunch is available at the Harvard Science Center and at numerous Harvard Square restaurants.
Session 320: Wednesday, 4 June 2014, 9:00 a.m.–6:30 p.m., Essex Ballroom and America Foyer
13. Elizabeth Brown and the Classification of Sunspots in the 19th Century
Kristine Larsen, Central Connecticut State University.
British amateur astronomers collected solar observation data as members of organizations such as the British Astronomical Association (BAA) and Liverpool Astronomical Society (LAS) in the late 1800s. Amateur astronomer Elizabeth Brown (1830-99) served as Solar Section Director of both groups, and not only aggregated solar observations (including hand-drawn illustrations) from observers from around the globe, but worked closely with solar astronomer Edward Maunder and other professionals in an attempt to garner specific types of observations from BAA members in order to answer a number of astronomical questions of the day. For example, she encouraged the monitoring of the growth and decay of sunspot groups and published a number of her own observations of particular groups, urging observers to note whether faculae were seen before the birth of sunspots in a given region, a topic of controversy at that time. She also developed a system for classifying sunspots and sunspot groups based on their appearance, dividing then into 11 types: normal, compound, pairs, clusters, trains, streams, zigzags, elliptical, vertical, nebulous, and dots. This poster will summarize Brown’s important contributions to solar observing in the late 19th century and situate her classification scheme relative to those of A.L. Cortie (1901), M. Waldmeier (1938; 1947) and the modified Zurich system of McIntosh (1966; 1969; 1989).
Session 306: Wednesday, 4 June 2014, 10:00–11:30 a.m., Gloucester Room
Session Chair:
10:30 4. Nova Discovery Efficiency 1890-2014; Only 43%±6% of the Brightest Novae Are Discovered
Bradley E. Schaefer, Lousiana State University.
Galactic nova discovery has always been the domain of the best amateur astronomers, with the only substantial exception being the use of the Harvard plates from 1890-1947. (Modern CCD surveys have not produced any significant nova discoveries.) From 1890-1946, novae were discovered by gentlemen who deeply knew the stars in the sky and who checked for new stars on every clear night. This all changed when war surplus binoculars became commonly available, so the various organizations (e.g., AAVSO, BAA) instructed their hunters to use binoculars to regularly search small areas of the Milky Way. In the 1970s the hunters largely switched to blinking photographs, while they switched to CCD images in the 1990s, all exclusively in Milky Way regions. Currently, most hunters use 'go-to' scopes to look deeply only in the Milky Way, use weekly or monthly cadences, never go outside to look up at the light-polluted skies, and do not have the stars memorized at all. This situation is good for catching many faint novae, but is inefficient for catching the more isotropic and systematically-fast bright novae. I have made an exhaustive analysis of all known novae to isolate the effects on the relative discovery efficiency as a function of decade, the elongation from the Sun, the Moon's phase, the declination, the peak magnitude, and the duration of the peak. For example, the relative efficiency for novae south of declination -33° is 0.5 before 1953, 0.2 from 1953-1990, and 0.8 after 1990. My analysis gives the overall discovery efficiency to be 43%±6%, 30%, 22%, 12%, and 6% for novae peaking brighter than 2, 4, 6, 8, and 10 mag. Thus, the majority of first magnitude novae are being missed. The bright novae are lost because they are too close to the Sun, in the far south, and/or very fast. This is illustrated by the discovery rate for Vpeak
10:40 5. The First Published Chart of the Andromeda Nebula, 1667
Owen Gingerich, Harvard University.
The Parisian astronomer Ismaél Bullialdus (1605–1694) is known for his planetary tables (Astronomia philolaica, 1645) based on a geometrical approximation to the Keplerian ellipse, and for his long correspondence with the Danzig astronomer Johannes Hevelius and with Christiaan Huygens. Bullialdus became interested in the nascent study of variable stars, and in 1667 published a small pamphlet with two contributions, one on Mira Ceti and the other on the nebula in Andromeda. He found a manuscript portraying the nebula with the date 1428, and because Tycho Brahe never mentioned a nebula in Andromeda, Bullialdus conjectured that this object was a variable that had disappeared in the intervening era. “We conclude this since this conglomeration was observed neither by Hipparchus nor anyone else in antiquity, nor in the previous age by Tycho, nor in the age of our forefathers like Bayer.” His publication included a handsome engraving of the image of Andromeda and the position of the nebula, its first printed chart. I recently acquired a copy of this rare pamphlet, Ad astronomos monita duo, and realized that the image matched a manuscript now in the Gotha Research Library, a 15th-century Latin version based on the work of the tenth-century Islamic astronomer, al-Sufi. The manuscript does not carry the name of al-Sufi, and hence Bullialdus had no real clue about its origin or its date of composition. Paul Kunitzsch (The Arabs and the Stars, 1989, Article XI, “The Astronomer Abu ’l-Husayn al-Sufi”) has identified a group of eight “Latin al-Sufi” manuscripts from this period, scattered in European libraries, but only the one now in Gotha is an exact match to Bullialdus’ engraving. The al-Sufi manuscript was given to the Gotha Library in 1798 by Duke Ernst II of Saxonia-Gotha-Altenburg, who must have acquired it from France sometime in the 18th century.
10:50 6. The Portrayal of the Medicean Moons in Early Astronomical Charts and Books
Michael Mendillo, Boston University.
Galileo’s talents in perspective and chiaroscuro drawing led to his images of the Moon being accepted as the portrayal of a truly natural physical place. The Moon was seen as a world — real but separate from Earth. In contrast to his resolved views of the Moon, Galileo saw the moons of Jupiter as only points of light, and thus in Sidereus Nuncius they appear as star-symbols. Within 50 years, in Cellarius' Atlas Coelestis seu Harmonia Macrocosmica (1660), the Medicean moons continue to appear in multiple charts as star-shaped symbols — in most cases equidistant from Jupiter. They appear in the Cellarius charts as updates to the cosmological systems of Copernicus and Tycho Brahe, but not in the charts devoted to the Ptolemaic system. A quarter century later, Mallet did not include the moons of Jupiter in his Copernican chart in Description de l’Universe (1683). Around 1690, in Jaillot’s Four Systems of Cosmology, the Medicean moons appear as circular symbols in four distinct concentric orbits around Jupiter. Additional examples appear in a later edition of Mallet (1690s), and in De Fer (1705), Dopplemayer (1720), and still later in Buy de Mornas (1761). As objects discussed in scientific books, symbolic representations of the Medicean moons appear in Marius (1614), Descartes (1644), Fontana (1646) and Hevelius (1647). A pictorial survey of antiquarian charts and books depicting the Medicean moons will be the focus of this presentation. As telescope sizes increased, the Galilean moons could be seen as extended objects, and thus the transition occurred from portraying the moons as points of light to disks with physically-meaningful details. Initially, these were done via drawings of glimpses of the disks of the four moons during moments of extremely good seeing (termed “lucky images” in the pre-adaptive optics period). This era of portraying surface characteristics of Io, Europa, Ganymede and Callisto by hand-drawn images from naked-eye observations ended in the 1970s when spaceflight missions to the outer planets returned photographic images.