Sunspot Positions and Areas from Observations by Pierre Gassendi

Vokhmyanin, Mikhail; Zolotova, N. V.

doi:10.1007/s11207-018-1372-8

Cited by 15 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result, which agrees fairly well with the existing distributions of contemporary sunspot observations by Scheiner (Arlt et al, 2016) and Malapert et al (Carrasco et al, 2019b), visualises sunspot migration during the declining phase of Solar Cycle −12. This confirms the hypothesis of the continuity of Solar Cycle −12 from 1621 to somewhere in 1631/1632 (Vokhmyanin and Zolotova, 2018b;Carrasco et al, 2019b).…”

Section: Discussionsupporting

confidence: 88%

Daniel Mögling’s Sunspot Observations in 1626–1629: A Manuscript Reference for the Solar Activity before the Maunder Minimum

Hayakawa

Iju

Murata

et al. 2021

ApJ

View full text Add to dashboard Cite

The sunspot groups have been observed since 1610 and their numbers have been used for evaluating the amplitude of solar activity. Daniel Mögling recorded his sunspot observations for more than 100 days in 1626-1629 and formed a significant dataset of sunspot records before the Maunder Minimum. Here, we have analysed his original manuscripts in the Universitäts-und Landesbibliothek Darmstadt (ULBD) to review Mögling's personal profile and observational instruments and derive number and positions of the sunspot groups. In his manuscript, we have identified 134 days with an exact sunspot group number and 3 days of additional descriptions. Our analyses have completely revised their observational dates and group number, added 19 days of hitherto overlooked observations, and removed 8 days of misinterpreted observations. We have also revisited sunspot observations of Schickard and Hortensius and revised their data. These results have been compared with the contemporary observations. Moreover, we have derived the sunspot positions from his sunspot drawings and located them at 2°-23° in the heliographic latitude in both solar hemispheres. Contextualised with contemporary observations, these results indicate their temporal migration to lower heliographic latitudes and emphasise its location in the declining phase

show abstract

Section: Discussionsupporting

confidence: 88%

Daniel Mögling’s Sunspot Observations in 1626–1629: A Manuscript Reference for the Solar Activity before the Maunder Minimum

Hayakawa

Iju

Murata

et al. 2021

ApJ

View full text Add to dashboard Cite

show abstract

“…Thus, solar activity could have gradually decreased from the beginning of the seventeenth century until the core of the MM. Recent research on the solar activity level from sunspot observations before the MM can be consulted, for example, in Vaquero et al (2011), Arlt et al (2016, Vokhmyanin & Zolotova (2018), and Carrasco et al (2019b. For example, values of the group sunspot number calculated by Vaquero et al (2011) from sunspot observations made by Marcgraf and others for the period 1937-1942 are compatible with those obtained in this work (Figure 5, bottom panel).…”

Section: An Estimation Of S N For the MMsupporting

confidence: 85%

Relationship between the Sunspot Number and Active Day Fraction: An Application for the Maunder Minimum

Carrasco

Llera

Aparicio

et al. 2022

ApJ

View full text Add to dashboard Cite

Long-term solar activity can be studied using several parameters. Some of the most used are based on the sunspot counting. The active day fraction (ADF) is the simplest index derived from this counting. It is reliable in periods of low solar activity such as the Maunder minimum (MM). In this work, we study the relationship between the ADF and the sunspot number. We have obtained that the optimal fit of that relationship is an exponential function whose exponent is a degree 3 polynomial including all data except those with ADF equal to 100%. Then, we use that fit to estimate the sunspot number during the MM from the ADF calculated from the most recent sunspot group number database. Our estimations of the annual sunspot numbers are below 15, except that for 1656, which is 40.8, whereas our estimations of the triennial sunspot numbers are below 10 from 1648 to 1714. We have found peaks of the solar cycle in the middle of the 1650s, 1670s, 1680s, and 1700s but no clear evidence of solar cycle in the 1660s and 1690s, likely due to the scarcity of the available data. Our results agree with previous works obtaining values significantly higher than those of the group sunspot number derived by Hoyt and Schatten in 1998 but still fully compatible with a grand minimum period.

show abstract

“…Since there is a reprint of the book from 1727 made in Florence, differences between the drawings in the two versions may indicate the uncertainties involved. Vokhmyanin and Zolotova (2018a) find from this comparison that the sunspot areas are particularly uncertain.…”

Section: Pierre Gassendimentioning

confidence: 81%

Historical sunspot records

Arlt

Vaquero

2020

Living Rev Sol Phys

105

View full text Add to dashboard Cite

Sunspot observations are available in fairly good numbers since 1610, after the invention of the telescope. This review is concerned with those sunspot observations of which longer records and drawings in particular are available. Those records bear information beyond the classical sunspot numbers or group sunspot numbers. We begin with a brief summary on naked-eye sunspot observations, in particular those with drawings. They are followed by the records of drawings from 1610 to about 1900. The review is not a compilation of all known historical sunspot information. Some records contributing substantially to the sunspot number time series may therefore be absent. We also glance at the evolution of the understanding of what sunspots actually are, from 1610 to the 19th century. The final part of the review illuminates the physical quantities that can be derived from historical drawings.

show abstract

Sunspot Positions and Areas from Observations by Pierre Gassendi

Cited by 15 publications

References 39 publications

Daniel Mögling’s Sunspot Observations in 1626–1629: A Manuscript Reference for the Solar Activity before the Maunder Minimum

Daniel Mögling’s Sunspot Observations in 1626–1629: A Manuscript Reference for the Solar Activity before the Maunder Minimum

Relationship between the Sunspot Number and Active Day Fraction: An Application for the Maunder Minimum

Historical sunspot records

Contact Info

Product

Resources

About