Sunspot numbers based on historic records in the 1610s: Early telescopic observations by Simon Marius and others

Abstract

Hoyt & Schatten (1998) claim that Simon Marius would have observed the sun from 1617 Jun 7 to 1618 Dec 31 (Gregorian calendar) all days, except three short gaps in 1618, but would never have detected a sunspot – based on a quotation from Marius in Wolf (1857), but mis‐interpreted by Hoyt & Schatten. Marius himself specified in early 1619 that for one and a half year... rather few or more often no spots could be detected... which was never observed before (Marius 1619). The generic statement by Marius can be interpreted such that the active day fraction was below 0.5 (but not zero) from fall 1617 to spring 1619 and that it was 1 before fall 1617 (since August 1611). Hoyt & Schatten cite Zinner (1952), who referred to Zinner (1942), where observing dates by Marius since 1611 are given but which were not used by Hoyt & Schatten. We present all relevant texts from Marius where he clearly stated that he observed many spots in different form on and since 1611 Aug 3 (Julian) = Aug 13 (Greg.) (on the first day together with Ahasverus Schmidnerus); 14 spots on 1612 May 30 (Julian) = Jun 9 (Greg.), which is consistent with drawings by Galilei and Jungius for that day, the latter is shown here for the first time; at least one spot on 1611 Oct 3 and/or 11 (Julian), i.e. Oct 13 and/or 21 (Greg.), when he changed his sunspot observing technique; he also mentioned that he has drawn sunspots for 1611 Nov 17 (Julian) = Nov 27 (Greg.); in addition to those clearly datable detections, there is evidence in the texts for regular observations. For all the information that can be compared to other observers, the data from Marius could be confirmed, so that his texts are highly credible. We also correct several shortcomings or apparent errors in the database by Hoyt & Schatten (1998) regarding 1612 (Harriot), 1615 (Saxonius, Tard´e), 1616 (Tard´e), 1617–1619 (Marius, Riccioli/Argoli), and Malapert (for 1618, 1620, and 1621). Furthermore, Schmidnerus, Cysat, David & Johann Fabricius, Tanner, Perovius, Argoli, and Wely are not mentioned as observers for 1611, 1612, 1618, 1620, and 1621 in Hoyt & Schatten. Marius and Schmidnerus are among the earliest datable telescopic sunspot observers (1611 Aug 3, Julian), namely after Harriot, the two Fabricius (father and son), Scheiner, and Cysat. Sunspots records by Malapert from 1618 to 1621 show that the last low‐latitude spot was seen in Dec 1620, while the first high‐latitude spots were noticed in June and Oct 1620, so that the Schwabe cycle turnover (minimum) took place around that time, which is also consistent with the sunspot trend mentioned by Marius and with naked‐eye spots and likely true aurorae. We consider discrepancies in the Hoyt & Schatten (1998) systematics, we compile the active day fractions for the 1610s, and we critically discuss very recent publications on Marius which include the following Maunder Minimum. Our work should be seen as a call to go back to the historical sources. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Sunspot positions, areas, and group tilt angles for 1611−1631 from observations by Christoph Scheiner

“…Scheiner (1573Scheiner ( -1650 belongs -together with Johannes Fabricius, Galileo Galilei, Thomas Harriot, Joachim Jungius, Si- Table 1. Numbers of days available for given years as reported by Scheiner (1630), Scheiner (1651), and Reeves & Van Helden (2010 (Neuhäuser & Neuhäuser 2016) -to the first observers who left records of sunspots seen through a telescope. Scheiner's first observations were made in early March 1611, together with the student Johann Baptist Cysat (1586-1657).…”

New sunspots and aurorae in the historical Chinese text corpus? Comments on uncritical digital search applications

“…The Chinese naked‐eye spot AD 1618 Jun 20–22 with the wording ri pang is corroborated by Malapert's drawings for June 21–29 (Neuhäuser & Neuhäuser , their fig. 2), which is not the only example.…”

“…This interpretation is arbitrary and no more than speculation in a philological view point (their footnote 14). First, we would like to note that it was not Neuhäuser & Neuhäuser () who suggested to correct the date given as intercalary 6th month in Ming shi and Tianwen zhi to intercalary 4th month , but Wittmann & Xu (), Yau & Stephenson (), and Xu et al (), as clearly referenced in Neuhäuser & Neuhäuser (, their section 3.2). Then, there are two more reports on this spot: Shenzong shilu clearly gives intercalary 4th month for three days until day wuzi (June 22), see Yau & Stephenson () and Xu et al (), and Songjiang Fuzhi gives 5th month, 1st day , that is, June 22 (Yau & Stephenson ).…”

“…Hayakawa et al () comment on this case that Neuhäuser & Neuhäuser ( ) relate this record [MS#S24] with … Malapert during 1618.06.21–29 … Neuhäuser & Neuhäuser ( ) interpret the misdated intercalary month of MS#S24 to intercalary fourth month to speculate this record as on 1618.06.20–22. This interpretation is arbitrary and no more than speculation in a philological view point (their footnote 14).…”

“…Among the nonprimary candidates, K+16 select those five records (two on the same date) with a lunar phase between 0.0 and 0.1 or between 0.9 and 1.0 as secondary candidates (their section 3.6). Only one of these five records is listed in Yau et al (), namely the one on AD 1618 Jul 19, for which Neuhäuser & Neuhäuser () noticed that it is simultaneous to the sunspot drawn by Malapert for AD 1618 Jul 7–19. Among those five records, four are within the Maunder Minimum on three different dates: AD 1650, 1667, and 1679.…”