Synoptic maps of solar coronal hole boundaries derived from He II 304 Å spectroheliograms from the manned Skylab missions

The disk boundaries of coronal holes have been determined from He II 304 Å spectroheliograms which were taken with the Naval research Laboratory (NRL) slitless XUV spectrograph during the manned Skylab missions. These boundaries are plotted by Carrington rotation as synoptic charts in both the standard rectangular as well as polar-view projections. The polar-view projections emphasize that the major areas occupied by coronal holes during this period were in the polar caps at latitudes °> 60° North and South. The periods of time for which boundaries were determined are 24 May through 23 June 1973 (first manned Skylab mission), 2 August through 24 September 1973 (second manned mission); and 21 November 1973 through 2 February 1974 (third manned mission); the Carrington rotations covered (in part or totally) are 1601 and 02; 1604, 05 and 06; and 1908, 09 and 10, respectively. These charts are presented for use in the study of Skylab and corroborating space/ground-based data taken during the manned mission periods. by J.D. Bohlin and D.M. Rubenstein ; E.O. Hulburt Center for Space Research, Naval Research Laboratory. "November 1975." Also available via the Internet. Includes bibliographical references (page 4). 1975 NESDIS (National Environmental Satellite, Data, and Information Service) Library Public Domain 2286