000003010 001__ 3010
000003010 005__ 20170106113523.0
000003010 0247_ $$2DOI$$a 10.1007/s11207-016-0982-2
000003010 037__ $$aSCART-2017-0006
000003010 100__ $$aVaquero, J. M. 
000003010 245__ $$aA Revised Collection of Sunspot Group Numbers
000003010 260__ $$c2016
000003010 500__ $$aSunspot Workshops 
000003010 520__ $$aWe describe a revised collection of the number of sunspot groups from 1610 to the present. This new collection is based on the work of Hoyt and Schatten ( Solar Phys. 179, 189, 1998). The main changes are the elimination of a considerable number of observations during the Maunder Minimum (hereafter, MM) and the inclusion of several long series of observations. Numerous minor changes are also described. Moreover, we have calculated the active-day percentage during the MM from this new collection as a reliable index of the solar activity. Thus, the level of solar activity obtained in this work is greater than the level obtained using the original Hoyt and Schatten data, although it remains compatible with a grand minimum of solar activity. The new collection is available in digital format.
000003010 594__ $$aSTCE
000003010 6531_ $$aSunspots
000003010 6531_ $$a statistics
000003010 6531_ $$aSolar cycle
000003010 6531_ $$aobservations
000003010 700__ $$aSvalgaard, L.
000003010 700__ $$aCarrasco, V. M. S.
000003010 700__ $$aClette, F.
000003010 700__ $$aLefèvre, L.
000003010 700__ $$aGallego, M. C.
000003010 700__ $$aArlt, R.
000003010 700__ $$aAparicio, A. J. P.
000003010 700__ $$aRichard, J.-G.
000003010 700__ $$aHowe, R.
000003010 773__ $$c3061-3074$$n9-10$$pSolar Physics$$v291$$y2016
000003010 8560_ $$flaure.lefevre@observatoire.be
000003010 905__ $$apublished in
000003010 980__ $$aREFERD