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J/A+A/599/A131      Butterfly diagram wings                  (Leussu+, 2017)

Wings of the butterfly: Sunspot groups for 1826-2015. Leussu R., Usoskin I.G., Senthamizh Pavai V., Diercke A., Arlt R., Mursula K. <Astron. Astrophys. 599, A131 (2017)> =2017A&A...599A.131L (SIMBAD/NED BibCode)
ADC_Keywords: Sun Keywords: Sun: activity - sunspots - history and philosophy of astronomy Abstract: The continuous spatio-temporal evolution (the so-called 'Maunder butterfly diagram') of sunspot activity was available since 1874 using data from the Royal Greenwich Observatory since 1875, extended by SOON network data after 1976. Here we present a new extended butterfly diagram of sunspot group occurrence continuously since 1826, using the recently digitized data from Schwabe (1826-1867) and Spoerer (1868-1874). The wings of the diagram are separated using a recently developed method based on long gaps in sunspot group occurrence in different latitude bands. Characteristic latitudes, corresponding to the start, end and the latitudinal span of the wings, F-, L- and H-latitudes, respectively, as well as times and asymmetries of the butterfly wings are analyzed. The F-latitude depict a weak tendency, especially in the S-hemisphere, to follow the wing strength (quantified in the total sum of monthly numbers of sunspot groups). The H-latitudes are highly significantly correlated with the strength of the wings during cycles 12-23. The L-latitudes show no clear relation to the wing strength. Overall, stronger cycle wings tend to start at higher latitudes and have greater wing's span. A strong (5-6)-cycle periodic oscillation was found in many latitudinal parameters, such as dates of the start and end of the wings and, most pronounced, in the difference between the wing lengths in the two hemispheres. A barely significant oscillation of about 10 cycles period is found in the asymmetry of the L-latitudes. The new long database of butterfly wings and the results based on it provide new observational constraints to the spatio-temporal distribution of sunspot occurrence and their solar cycle related time-latitude evolution. Description: fig1data.dat contains the separated wings in a butterfly diagram for sunspot groups from three different origins: Sunspot observations by S.H. Schwabe and G. Spoerer, and the RGO/SOON compilation. The latitudes for sunspot groups from the Schwabe and Spoerer data are given as size-weighted averages from sunspots belonging to each group. Latitudes for the RGO compilation are given as they are stated in the original data. The columns report the year, month, day, date [yr], latitude [deg], cycle, hemisphere, and data set tag. Northern hemisphere wings are tagged with "1" and southern hemisphere wings with "2". The data set tag is "1" for Schwabe data, "2" for Spoerer data and "3" for RGO data. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file fig1data.dat 32 52804 Butterfly diagram wings for solar cycles 7-24
See also: VI/138 : Sunspots catalogues, 1853-1870 (Casas+, 2013) Byte-by-byte Description of file: fig1data.dat
Bytes Format Units Label Explanations
1- 10 A10 "date" Obs.Date Observation date 12- 19 F8.3 yr Date Date in fractions of year 21- 25 F5.1 deg LAT Latitude, negative for southern hemisphere 27- 28 I2 --- C [7/24] Cycle number (7-24) 30 I1 --- W [1/2] Hemisphere (1: north, 2: south) 32 I1 --- D [1/3] Data set (1: Schwabe, 2: Spoerer, 3: RGO)
Acknowledgements: Ilya Usoskin, ilya.usoskin(at)
(End) Patricia Vannier [CDS] 12-Dec-2016
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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