CAOSP abstracts, Volume: 41, No.: 2, year: 2011

Abstract: Spectroheliograms in the Astronomical Observatory of the Coimbra University (Portugal) have been photographed in the spectral line of Ca II K continuously since 1926 and, since 1989, spectroheliograms in Hα have been photographed as well. Since 2007, all the spectroheliograms have been recorded using a CCD camera. Until July 2010, about 34 000 observations in total were acquired in the spectral bands Ca II K3, Ca II K1, Hα, red continuum, and Hα Dopplergrams (since 2009), covering a period of 85 years (Ca II K3 line). We describe the characteristics of the photographic and digital spectroheliograms, the statistics of the observations, and the utilization of Coimbra spectroheliograms by the solar community.