A solar cycle lost in 1793--1800: Early sunspot observations resolve the old mystery

Abstract

Because of the lack of reliable sunspot observation, the quality of sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784--1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18--19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e. the latitudinal distribution of sunspots in the 1790's. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793--1796 unambiguously shows that a new cycle started in 1793, which was lost in traditional Wolf's sunspot series. This finally confirms the existence of the lost cycle that has been proposed earlier, thus resolving an old mystery. This letter brings the attention of the scientific community to the need of revising the sunspot series in the 18th century. The presence of a new short, asymmetric cycle implies changes and constraints to sunspot cycle statistics, solar activity predictions, solar dynamo theories as well as for solar-terrestrial relations.

arXiv commentPublished by Astrophys. J. Lett

References in corpus (2)

• Historical Sunspot Observations: A Review
• The butterfly diagram in the 18th century

Cited by in corpus (36)

• Revisiting the Sunspot Number
• Solar cycle prediction
• Wotan: Comprehensive time-series de-trending in Python
• The Maunder minimum (1645--1715) was indeed a Grand minimum: A reassessment of multiple datasets
• A Revised Collection of Sunspot Group Numbers
• A History of Solar Activity over Millennia
• Multiple dynamo modes as a mechanism for long-term solar activity variations
• Re-calibration of the Sunspot Number: Status Report
• The solar magnetic field since 1700: II. Physical reconstruction of total, polar and open flux
• Secular variation of hemispheric phase differences in the solar cycle
• Variations of the solar cycle profile in a solar dynamo with fluctuating dynamo governing parameters
• Studies of grand minima in sunspot cycles from a flux transport solar dynamo model
• Neural Network Forecast of the Sunspot Butterfly Diagram
• Thaddäus Derfflinger's sunspot observations during 1802-1824: A primary reference to understand the Dalton Minimum
• Solar activity around AD 775 from aurorae and radiocarbon
• Photometry's bright future: Detecting Solar System analogues with future space telescopes
• A Simple Method to Check the Reliability of Annual Sunspot Number in the Historical Period 1610-1847
• Robustness of Solar-Cycle Empirical Rules Across Different Series Including an Updated ADF Sunspot Group Series
• Revised Group Sunspot Number for 1640, 1652, and 1741
• The Dalton Minimum and John Dalton's Auroral Observations
• Strong evidence of low levels of solar activity during the Maunder Minimum
• Christian Horrebow's Sunspot Observations -- II. Construction of a Record of Sunspot Positions
• Phase coherence and phase jumps in the Schwabe cycle
• The Solar Corona during the Total Eclipse on 16 June 1806: Graphical Evidence of the Coronal Structure during the Dalton Minimum
• Iwahashi Zenbei's Sunspot Drawings in 1793 in Japan
• Reversals of Gnevyshev-Ohl rule
• Variations of 14-C around AD 775 and AD 1795 - due to solar activity
• Revisiting Kunitomo's Sunspot Drawings during 1835-1836 in Japan
• The lost sunspot cycle: New support from Be10 measurements
• Predictions of the Maximum Amplitude, Time of Occurrence, and Total Length of Solar Cycle 24
• Spatial-temporal forecasting the sunspot diagram
• Phase relationships of solar hemispheric toroidal and poloidal cycles
• On the current solar magnetic activity in the light of its behaviour during the Holocene
• Detection of Solar Filaments using Suncharts from Kodaikanal Solar Observatory Archive Employing a Clustering Approach
• 155-day Periodicity in Solar Cycles 3 and 4
• Sunspot positions from observations by Flaugergues in the Dalton Minimum