Ca K spectroheliograms from Mount Wilson Observatory have been re-processed, including a better correction for vignetting and more uniform intensity scaling. New synoptic maps were created.
Long term study of the solar filaments from the Synoptic Maps as derived from Hα Spectroheliograms of Kodaikanal Observatory (https://arxiv.org/abs/1707.05658)
Here is new our website from Kislovodsk Mountain Astronomical Station (KMAS) presenting information of daily and archive data: www.observethesun.com
Features to be displayed (e.g., sunspot, filaments, corona, coronal holes etc) could be selected on the left side of solar disk. Moving the mouse over the feature will show detailed information related to that feature.
(from A. Tlatov)
Digitization of Mount Wilson sunspot drawings has been completed. Description of the dataset and known issues are included in Pevtsov et al (2019, A&A, submitted).