Sunspot drawings by Japanese official astronomers in 1749–1750

Hayakawa, Hisashi; Iwahashi, Kiyomi; Fujiyama, Masashi; Kawai, Toshiki; Toriumi, Shin; Hotta, Hideyuki; Iijima, Haruhisa; Imada, Shinsuke; Shibata, Kazunari

doi:10.1093/pasj/psy066

Cited by 13 publications

(10 citation statements)

References 41 publications

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“…Although sunspot observations were mainly made in Europe, observations were also made in other parts of the world. In the oriental context, Hayakawa et al (2018a) presented sunspot observations made by the official Japanese astronomers in 1749 and 1750. There are 15 drawings of telescopic observations.…”

Section: Other Observers Before the Dalton Minimummentioning

confidence: 99%

Historical sunspot records

Arlt

Vaquero

2020

Living Rev Sol Phys

103

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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.

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Section: Other Observers Before the Dalton Minimummentioning

confidence: 99%

Historical sunspot records

Arlt

Vaquero

2020

Living Rev Sol Phys

103

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“…Four of his telescopes, which have a brass mirror tube and pedestal, are currently known. All of them have a Huygens eyepiece (Tomita et al, 1998) a zonglas (sunglass in Dutch), a colored filter glass to reduce the light passing through, which was imported to Japan until the mid 18th century from the Netherlands (e.g., Zuidelvaart, 1993;Hayakawa et al, 2018aHayakawa et al, , 2018b. These telescopes were investigated by Tomita et al (1998) and Ota (2003).…”

Section: Telescopes Used In Knitomo's Observationsmentioning

confidence: 99%

“…After a cultural contact with European astronomers, East Asian astronomers also began to undertake telescopic observations of sunspots activity (e.g. Kanda, 1932;Yamamoto, 1935;Kanda, 1960;Tomita et al, 1998;Kubota and Suzuki, 2003;Tamazawa et al, 2017b;Hayakawa et al, 2018aHayakawa et al, , 2018b.…”

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confidence: 99%

Revisiting Kunitomo’s Sunspot Drawings During 1835 – 1836 in Japan

et al. 2019

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We revisit the sunspot drawings made by the Japanese astronomer Kunitomo Toubei during 1835-1836 and recount the sunspot group number for each image. There are two series of drawings, preliminary (P, containing 17 days with observations) and summary (S, covering 156 days with observations), all made using brush and ink. S is a compilation of drawings for the period from February 1835, to March 1836. Presently, the P drawings are available only for one month, September 1835; those of other periods have presumably been lost. Another drawing (I) lets us recover the raw group count (RGC) for 25 September 1836, on which the RGC has not been registered in the existing catalogs. We also revise the RGCs from P and S using the Zürich classification and determine that Kunitomo's results tend to yield smaller RGCs than those of other contemporary observers. In addition, we find that Kunitomo's RGCs and spot areas have a correlation (0.71) that is not very different from the contemporary observer Schwabe (0.82).Although Kunitomo's spot areas are much larger than those determined by Schwabe due to skill and instrument limitations, Kunitomo at least captured the growing trend of the spot activity in the early phase of the Solar Cycle 8. We also determine the solar rotation axis to estimate the accurate

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“…where r in is the inner radius of the accretion disc) was ξ = −0.425, larger than what is expected from the typical ξ = −0.75 in "steady-state" accretion discs, but in-line with an irradiated accretion disc (Hayakawa 1981) which is expected in this system due to the strength of the detected X-ray source. To ensure this choice of ξ was not biasing our results, we also ran a Markov chain Monte Carlo (MCMC) as implemented as part of the ELC package (see Tegmark et al 2004) with ξ free.…”

Section: Orbital Modulationmentioning

confidence: 56%

Optical, X-ray, and γ-ray observations of the candidate transitional millisecond pulsar 4FGL J0427.8-6704

Kennedy

Breton

Clark

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We present an optical, X-ray, and γ-ray study of 1SXPS J042749.2-670434, an eclipsing X-ray binary which has an associated γ-ray counterpart, 4FGL J0427.8-6704. This association has led to the source being classified as a transitional millisecond pulsar (tMSP) in an accreting state. We analyse 10.5 years of Fermi LAT data, and detect a γ-ray eclipse at the same phase as optical and X-ray eclipses at the >5σ level, a significant improvement on the 2.8σlevel of the previous detection. The confirmation of this eclipse solidifies the association between the X-ray source and the γ-ray source, strengthening the tMSP classification. However, analysis of several optical data sets and an X-ray observation do not reveal a change in the source's median brightness over long timescales or a bi-modality on short timescales. Instead, the light curve is dominated by flickering which has a correlation time of 2.6 min alongside a potential quasi-periodic oscillation at ∼21 min. The mass of the primary and secondary star are constrained to be M 1 = 1.43 +0.33 −0.19 M and M 2 = 0.3 +0.17 −0.12 M through modelling of the optical light curve. While this is still consistent with a white dwarf primary, we favour the transitional millisecond pulsar in a low accretion state classification due to the significance of the γ-ray eclipse detection.

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Sunspot drawings by Japanese official astronomers in 1749–1750

Cited by 13 publications

References 41 publications

Historical sunspot records

Historical sunspot records

Revisiting Kunitomo’s Sunspot Drawings During 1835 – 1836 in Japan

Optical, X-ray, and γ-ray observations of the candidate transitional millisecond pulsar 4FGL J0427.8-6704

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