Yerkes Lunar1 and Lunar2 Moon plates Background Interest in producing better quality maps of the Moon based on photography arose in the 1950s. This became a priority when, after Sputnik, it was obvious that the Moon would become a target for in-situ exploration. Gerald Kuiper, first at Yerkes and later at the Lunar and Planetary Laboratory at the University of Arizona, directed a project to collect high-quality photographs of all lunar areas. These included both archival pictures as well a new ones, many of which were taken at Yerkes Observatory. These photographs were used to produce three books: the Photographic Lunar Atlas (1960), the Orthographic Atlas of the Moon (1961) and the Rectified Lunar Atlas (1963). Many of the plates in this series were used for those works. The Telescope: The plates listed here were taken with the Yerkes Observatory 40-inch (102-cm) aperture f/19 refractor. The plate scale is 10.65"/mm which allowed for the full lunar disk to be imaged on an 8 x 10-inch plate. Many exposures were taken with the telescope aperture reduced. The geographic location of the observatory is: longitude = 88° 33’ W, latitude = 42° 34’ N. The Plates The two logbooks indicate 1809 lunar plates (denoted L plates) plus 10 platee labeled TP (test plate?), but many listed plates are not available. The logbook states that entries with a red dash [through the plate number] indicates that plate was "discarded (into discard file)" and entries with their plate number crossed out in blue indicates the plate was "thrown out completely." Plates so marked that were not found in the plate archive are labeled in this catalog as discarded. The plates are 8 x 10-inch in size. Some plates also had star trail exposures, and the plate numbers of these these are marked with an asterisk. These exposures are denoted is this catalog with ST* as the object. The TP plates are listed at the end of the catalog as well as in their chronological place, with these plates filed before the regular L-series plates in the plate archive. The Logbook These plates were recorded in two logbooks called Lunar 1 and Lunar 2. The books are archived at the University of Chicago. Both logbooks have been scanned with the scans available on-line. There is an additional notebook (denoted the Red Folder) which has not yet been scanned. This book contains calculated quantities for many of the plates including Term., 𝞴, Lib. 𝞫, and Yerkes which have been incorporated into this catalog although it is not fully clear what these represent. It is assumed they refer to the terminator location, libration in longitude and latitude and (as a guess) the coordinates of Crater Yerkes in some system. The Red Folder also has a table of the number of plates of different quality taken on each night. The Searchable file The comma separated "Lunar-Plates.csv" file can be viewed online or downloaded to search for plates of interest. The file lists the plates in chronological order, which is essentially plate number order. The data can, of course, be sorted by any other listed parameter. Any blank cell in the Lunar-Plates.csv file indicates that information is missing or it has yet to be calculated. Description of the columns of the Lunar-Plates.csv file RCD - Record number in the Lunar-Plates.csv catalog Plate No - Identifying number of the plate, either L, TP or ST*; ST* indicates an asterisk on the L plate number in the logbook denoting a plate with a star trail Object - Usually moon, but at times star trail or a planet UT Date - The UT date the plate was exposed as recorded UT Time - UT time of exposure as listed. Notes indicate some needed a correction which was applied in this catalog Exposure - Exposure length (in seconds unless otherwise noted); some exposures are labeled "DIA" or "D" and TER" or "T" but the meaning of these is unknown. Aperture (inches) - The effective aperture of the telescope (which was often stopped down from its full 40-inches) Termin - Reference to terminator location with ET = an evening terminator and MT = a morning terminator (from the Red Folder) Lib L - Libration in longitude (assumed meaning of 𝞴 ) (from the Red Folder) Lib b - Libration in latitude (assumed meaning of Lib. 𝞫) (from the Red Folder) Yerkes - Two coordinates of unknown meaning (possibly refer to lunar crater Yerkes) Emulsion - Photographic emulsion of the plate Seeing - Atmospheric seeing, often on a scale of 1 (worst) to 5 (best) Trans - Atmospheric transparency on scale of 1 (worst) to 5 (best) Quality - Plate quality, the first number seems to be overall quality on a scale of 0(zero) to 7 (seven) (from the Red Folder) Observer - Recorded observer (see list below) Location - Location of plate when this catalogue was prepared: Yerkes plate vault, plate discarded, plate missing HA - Telescope hour angle at time of exposure Dec - Telescope declination at time of exposure (usually for the star trail exposures) Notes - Notes recorded in the log book List of Observers: DWGA = Douglas W. G. Arthur EM = Elliott Moore EAW = Ewan A. Whitaker DC = Dale Cruickshank CH = Carl Hullen AB = Alan Binder GPK = Gerard P. Kuiper