This is a sequence of solar synoptic maps covering Solar Cycle 23.
The SOHO spacecraft began collecting this data in May of 1996, near the beginning (minimum) of the sunspot cycle. The sequence is projected in cylindrical-equidistant (CED) coordinates suitable for reprojection on spheres for animation or visualization purposes. These images are not suitable for scientific analysis.
The original data were collected in FITS format from the SOHO/MDI archive, one image for each Carrington Rotation, which are 27.2753 days long.
Solar minimum for Cycle 23 was in May 1996 (Carrington Rotation #1909), solar maximum around March 2000 (Carrington Rotation #1960), with a return to minimum about October 2008 (Carrington Rotation #2075). There are two gaps in the sequence, totalling four rotations, at Carrington rotations #1938, 1939, 1940, 1941, and 1998. These images are missing from the sequence due to SOHO being offline. Gaps in the data coverage for individual maps (occasional day outages or poor coverage near the poles of the Sun) were filled using data accumulated from previous maps.
IMPORTANT NOTE: These images are for visualization purposes only. They are not suitable for scientific analysis.