First Star PhotographIn 1850, the first photograph of a star was made. At Harvard Observatory (founded 1839), the observatory director, William Cranch Bond and a Boston photographer John Adams Whipple took a daguerreotype of Vega. (A daguerreotype used a copper base with a thin film of polished silver sensitized by iodine vapors to form a thin yellow layer of silver iodide. After the photograph was taken, the plate was developed in a current of magnesium vapor at 75ºC, which adhered to the light-struck parts of the plate. The plate was then fixed in sodium thiosulfate, and rinsed.) Overall, this process to take an image of a star or nebula took many hours of patient skill. Fortunately better photographic materials were later invented. |
