Reading Nature, Observing Science: Examining Material Practices in the Lick Observatory Archives and Kenneth S. Norris PapersMain MenuIntroduction to the Lick Observatory ArchivesThe Lick Observatory: Imaging the CosmosThe Lick Observatory: Eclipse ExpeditionsEclipse Intro page (first in a path)Introduction to Kenneth S. Norris PapersKenneth S. Norris Papers: Natural History in PracticeKenneth S. Norris Papers: Pedagogy and ConservationConnections: In Relation to NatureThese images demonstrate the different constructions of nature in the two archivesConnections: Materials of ObservationVisualization of the ConnectionsVisualizes the connections between all the contentReading Nature, Observing ScienceCaptions and information for the cases of objects on display at UCSC Special CollectionsAlex Moore6cd84a9f7efd71803c15562e48a509db9e0bb5a6Christine Turkb279a3dcf419860f915007f04f08e6fc0f8662ceDanielle Crawford22ce6a14f83c9ff73c3545a665951a092258f08e
Group of Sun Spots and Veiled Spots
12016-06-04T16:44:58-07:00Alex Moore6cd84a9f7efd71803c15562e48a509db9e0bb5a691841Illustration of Sun Spots by E.L. Trouvelot, 1875plain2016-06-04T16:44:59-07:00Alex Moore6cd84a9f7efd71803c15562e48a509db9e0bb5a6
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12016-06-04T10:01:39-07:00Alex Moore6cd84a9f7efd71803c15562e48a509db9e0bb5a6Understanding the SunAlex Moore23This group of illustrations and photographs traces the struggle of astronomers in the late nineteenth and early twentieth century to understand the sun, particularly the nature of sun spots and the solar corona.plain2016-06-10T15:56:05-07:00Alex Moore6cd84a9f7efd71803c15562e48a509db9e0bb5a6
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12016-06-04T10:01:39-07:00Understanding the Sun23This group of illustrations and photographs traces the struggle of astronomers in the late nineteenth and early twentieth century to understand the sun, particularly the nature of sun spots and the solar corona.plain2016-06-10T15:56:05-07:00The Lick Observatory eclipse expeditions strove to answer the following questions:
What is the solar corona?
Why does the sun have a corona?
Can General Relativity be proved?
Are there other planets or unknown bodies revolving around the sun?
Astrophysicists today understand sun spots to be magnetic areas of the sun's surface that appear dark because they are cooler than their surroundings (but still approximately 4500 degrees Celsius). The number and location of sun spots varies over an eleven year cycle, which coincides with magnetic activity and solar brightness. The Solar Corona is the sun's outer atmosphere and is understood to be made up of super-heated gasses that are formed into loops, plumes, and streamers by the sun's magnetic field.
Though sun spots were first observed by Galileo in 1610, the nature of both sunspots and the solar corona fascinated and mystified astronomers through the early nineteenth century. With the advent of astrophotography, astronomers could carefully observe and record these phenomena. In the carefully observed drawing by Langley the sun spot looks like a dark opening in a dense wall of foliage-like fibers. In Trouvelot's illustration, the sun spots are holes connected by masses that we would now understand to be prominences, but which here resemble muscle tissue. In both images we see careful observation of the visually available information--an interruption of the surface; a darker center surrounded by areas of movement--but interpreted with reference to familiar forms. These images reflected and informed Lick Director Edward Holden's thinking about the sun: both Trouvelot and Langley were in correspondence with the astronomers at the Lick, sharing sketches of their observations, and Holden pasted a copy of Langley's Sun Spot engraving into his scrapbook.
Similarly, the sketches astronomers made of the corona at this point in time accurately record the shapes of the corona, but fail to understand the forces behind it. Edward Holden, the founding Director of the Lick, hypothesized that the "coronal filaments were produced by streams of meteorites falling into the sun." John Schaeberle, the astronomer who designed the 40ft camera used on the majority of the eclipse expeditions, proposed that the coronal forms were "produced by volcanic forces emanating from the sun spots." It was not until the 1930s that the magnetic nature of the corona was understood amongst astronomers.
Today, astronomers can capture the the movements of the sun's surface with video and at multiple wavelengths. However, we still have questions about this giant magnetic star.