A Sunspot Catalog by Rafael Carrasco at the Madrid Astronomical Observatory for the Period 1931 – 1933

Aparicio, A. J. P.; Carrasco, V. M. S.; Gallego, M. C.; Vaquero, J. M.

doi:10.1007/s11207-022-01992-9

Cited by 4 publications

(3 citation statements)

References 31 publications

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“…Moreover, several sunspot catalogs were published by the observatory: the Aguilar catalog covering observations from 1914 to 1920 (Lefèvre et al, 2016), the Carrasco catalog including records for the period 1931 -1933 (Aparicio et al, 2022a), and the "modern" catalog with observations for 1952-1986(Aparicio et al, 2018. In addition to the sunspot observations, other solar features of the Sun were observed at the Madrid Astronomical Observatory such as prominences and chromospheric faculae (flocculi) (López Arroyo, 2004).…”

Section: Introductionmentioning

confidence: 99%

Rediscovering the observations of solar prominences from 1906 to 1957 recorded at the Madrid Astronomical Observatory

Aparicio¹,

Carrasco²,

Gallego³

et al. 2023

J. Space Weather Space Clim.

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The Madrid Astronomical Observatory implemented a solar observation program from 1876 to 1986. In addition to sunspots, the observers at this observatory recorded other solar features such as prominences. In this work, we have consulted the documentary sources of the Madrid Astronomical Observatory (the information is not digitally available), digitized the records of the observers on the annual number of prominences, and constructed a homogeneous series of the total and hemispheric annual number of prominences with heights of 25’’ and more for the period 1906 – 1957. To evaluate the quality of the data and assess their potential, we have compared the Madrid prominence series with the number of prominences recorded by the Astronomical Observatory of the University of Coimbra and other time series such as the sunspot number index, solar radio flux at 10.7 cm, and sunspot areas. We have also analyzed the hemispheric prominence numbers and the asymmetry index. We obtained the strongest correlation between Madrid and Coimbra prominence series (r = 0.7), whereas the correlations between Madrid prominence series and the other solar activity time series are similar (r ≈ 0.6). In addition, we found that the correlation coefficient between the Madrid prominence series and the sunspot number is lower than that from Coimbra prominence series and the sunspot number. We suggest that these differences are a consequence of the way prominences were counted in the Madrid Astronomical Observatory.

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Section: Introductionmentioning

confidence: 99%

Rediscovering the observations of solar prominences from 1906 to 1957 recorded at the Madrid Astronomical Observatory

Aparicio¹,

Carrasco²,

Gallego³

et al. 2023

J. Space Weather Space Clim.

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“…Chatterjee et al (2020) studied the latitude distribution of prominences for 10 solar cycles (Solar Cycle 15-24) from data recorded at the observatories of Kodaikanal, Meudon, and Kanzelhohe, and Carrasco et al (2019) Some historical sunspot catalogs by professional observatories, including records on different solar parameters such as latitudes and areas, have been also digitized. Some examples are those published by Carrasco et al (2014Carrasco et al ( , 2018, Lefèvre et al (2016), Aparicio et al (2018), Aparicio et al (2022b), and de Paula & Curto (2020) on the Iberian observatories of Madrid, Valencia, Ebro, and Coimbra and those published by Mandal et al (2017) and Ravindra et al (2020) on the sunspot number and area series from Kodaikanal. Moreover, Willis et al (2013aWillis et al ( , 2013b and Erwin et al (2013) analyzed the errors included in the catalog of the Royal Greenwich Observatory, whereas Baranyi et al (2016) published an overview of the sunspot observation series of the Debrecen Heliophysical Observatory.…”

Section: Introductionmentioning

confidence: 99%

A Catalog of Faculae, Prominences, and Filaments for the Period 1929–1944 from the Astronomical Observatory of the University of Coimbra

Carrasco

Vaquero

2022

ApJS

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The Astronomical Observatory of the University of Coimbra (Portugal) published a catalog with solar observations such as sunspots, faculae, prominences, and filaments for the period 1929–1944. In previous works, a machine-readable version on sunspot observations made in Coimbra was published. Here we extend that work and present a digital version of the facula, prominence, and filament observations made in that observatory. We have applied a quality control to the catalog, obtaining that the percentage of problematic or suspicious data found is lower than 1% of the total number of observations. In addition, we show an analysis of this catalog, as well as some comparisons between solar indices calculated from Coimbra data and those from other sources. Historical observations of faculae, prominences, and filaments are not as common as sunspot records, and in addition, few historical series of these solar features are available in digital version. For that reason, the catalog of solar observations published by the Coimbra Observatory is of enormous value. The recovery, publication, and availability of this catalog provide the scientific community with a valuable data set of solar characteristics that will help us to study in more detail the past solar magnetic field and long-term solar activity.

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“…Traditionally, such attribution was done manually, and inserted into catalogs and databases along with metadata related to the number of spots and groups, position, and area of each sunspot. Examples of such catalogs include the merged catalog from Lefevre & Clette, 2014, the US Air Force/SOON catalog (SOON, 2008), Debrecen's Photoheliographic data (DPD), Hungary (Baranyi et al, 2016;Győri et al, 2017), the Spanish observatories catalogs (Aparicio et al, 2014(Aparicio et al, , 2022Curto et al, 2016), and the Coimbra Observatory catalog, Portugal (Carrasco et al, 2018).…”

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confidence: 99%

SunSCC: Segmenting, Grouping and Classifying Sunspots From Ground‐Based Observations Using Deep Learning

Sayez,

De Vleeschouwer,

Delouille

et al. 2023

JGR Space Physics

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We propose a fully automated system to detect, aggregate, and classify sunspot groups according to the McIntosh scheme using ground‐based white light (WL) observations from the USET facility located at the Royal Observatory of Belgium. The sunspot detection uses a Convolutional Neural Network (CNN), trained from segmentation maps obtained with an unsupervised method based on mathematical morphology and image thresholding. Given the sunspot mask, a mean‐shift algorithm is used to aggregate individual sunspots into sunspot groups. This algorithm accounts for the area of each sunspot as well as for prior knowledge regarding the shape of sunspot group. A sunspot group, defined by its bounding box and location on the Sun, is finally fed into a CNN multitask classifier. The latter predicts the three components Z, p, and c in the McIntosh classification scheme. The tasks are organized hierarchically to mimic the dependency of the second (p) and third (c) components on the first (Z). The resulting CNN‐based segmentation is more accurate than classical unsupervised methods, with an enhancement up to 16% of F1 score in detection of the smallest sunspots, and it is robust to the presence of clouds. The automated clustering method was able to separate groups with an accuracy of 80%, when compared to hand‐made USET sunspot group catalog. The CNN‐based sunspot classifier shows comparable performances to methods using continuum as well as magnetogram images recorded by instruments on space mission. We also show that an ensemble of classifiers allows differentiating reliable and potentially incorrect predictions.

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A Sunspot Catalog by Rafael Carrasco at the Madrid Astronomical Observatory for the Period 1931 – 1933

Cited by 4 publications

References 31 publications

Rediscovering the observations of solar prominences from 1906 to 1957 recorded at the Madrid Astronomical Observatory

Rediscovering the observations of solar prominences from 1906 to 1957 recorded at the Madrid Astronomical Observatory

A Catalog of Faculae, Prominences, and Filaments for the Period 1929–1944 from the Astronomical Observatory of the University of Coimbra

SunSCC: Segmenting, Grouping and Classifying Sunspots From Ground‐Based Observations Using Deep Learning

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