208 citations · 1.6k across the 48 of their papers we have counts for
48 papers
Sunspot positions from observations by Flaugergues in the Dalton Minimum
Egor Illarionov, Rainer Arlt
French astronomer Honoré Flaugergues compiled astronomical observations in a series of hand-written notebooks for 1782$\unicode{x2013}$1830, which are preserved at Paris Observator…
Re-calibration of the Sunspot Number: Status Report
F. Clette, L. Lefèvre, T. Chatzistergos +18
We report progress on the ongoing recalibration of the Wolf sunspot number (SN) and Group sunspot number (GN) following the release of version 2.0 of SN in 2015. This report consti…
Tau Herculids 2022: Rate, number density, population index and geometrical effects from visual data
Jurgen Rendtel, Rainer Arlt
We analysed visual observation data of the Tau Herculids collected between 2022 May 28 and June 1. The population index for the entire sample is 2.4. For the pre-peak period we fin…
Reconstruction of the Solar Activity from the Catalogs of the Zurich Observatory
Egor Illarionov, Rainer Arlt
Catalogs of the Zurich Observatory contain positional information on sunspots, prominences and faculae in late 19th and early 20th centuries. This database is given in handwritten…
Revisiting the Amplitude of Solar Cycle 9: The Case of Sunspot Observations by W.C. Bond
V. M. S. Carrasco, M. C. Gallego, R. Arlt +1
William Cranch Bond, director of the Harvard College Observatory in mid-19th century, carried out detailed sunspot observations during the period 1847-1849. We highlight Bond was t…
Sunspot characteristics at the onset of the Maunder Minimum based on the observations of Hevelius
V. M. S. Carrasco, J. M. Vaquero, M. C. Gallego +8
An analysis of the sunspot observations made by Hevelius during 1642-1645 is presented. These records are the only systematic sunspot observations just before the Maunder Minimum.…