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The Astronomical Observatory of the University of Coimbra (Portugal) published a catalog with solar observations such as sunspots, faculae, prominences, and filaments for the period 1929–1944. In previous works, a machine-readable version on sunspot observations made in Coimbra was published. Here we extend that work and present a digital version of the facula, prominence, and filament observations made in that observatory. We have applied a quality control to the catalog, obtaining that the percentage of problematic or suspicious data found is lower than 1% of the total number of observations. In addition, we show an analysis of this catalog, as well as some comparisons between solar indices calculated from Coimbra data and those from other sources. Historical observations of faculae, prominences, and filaments are not as common as sunspot records, and in addition, few historical series of these solar features are available in digital version. For that reason, the catalog of solar observations published by the Coimbra Observatory is of enormous value. The recovery, publication, and availability of this catalog provide the scientific community with a valuable data set of solar characteristics that will help us to study in more detail the past solar magnetic field and long-term solar activity.

The effects of solar activity on technology have increased the interest in solar forecasting both in the scientific community and in society. With two and a half years of data available, we are approximately halfway to the maximum of Solar Cycle 25. Several research groups around the world published their predictions for this cycle. In this work, we assess the forecast made by the Solar Cycle 25 Prediction Panel. Analyzing the sunspot number data available, we conclude that Solar Cycle 25 is one of the weakest cycles since mid-18th century and, however, it is stronger than the initial forecast of the highest range predicted by the Solar Cycle 25 Prediction Panel for the two first years and a half of its ascending phase.

Long-term studies on hemispheric asymmetry can help to understand better the solar dynamo. We present the hemispheric sunspot number calculated from daily sunspot observations made at the Madrid Astronomical Observatory for the period 1935–1986 (corresponding approximately to Solar Cycles 17–21). From this data set, we also analyzed the asymmetry index and hemispheric phase shifts. We conclude that the northern hemisphere was predominant in Solar Cycles 17–20, whereas the southern hemisphere was predominant in Solar cycle 21. The strongest asymmetries are found in Solar Cycles 20 (with a relative difference between both hemispheres of 44%) and 19 (39%). A normalization of the Madrid hemispheric sunspot number was also made with respect to the sunspot number (Version 2). Our results agree with previous studies on hemispheric asymmetry around the mid-20th century and their secular trends.