Results of 20-year solar observations in the He I λ 1083 nm line at the Crimean Astrophysical Observatory

Abstract

During 1999–2018, an extensive dataset of images of the solar disk in the He I λ 1083 nm line was acquired at the Crimean Astrophysical Observatory (CrAO) with the Solar Tower Telescope – 2 (STT-2). Over this period, the image processing underwent various changes. No observations were carried out from mid-2018 to the end of 2019. In 2020, the process of observations and image processing at the telescope was modernized. Currently, all images acquired during different periods prior to modernization are being processed using a unified method to form a catalog. This work presents a brief historical overview of observations in the He I λ 1083 nm line at CrAO, a concise description, and fragments from the catalog.