Sunspot numbers obtained by different networks in 1997 ====================================================== SIDC SONNE SONNE AAVSO AKS BAA GFOES OAA RWG TOS VVS prov. prov. def. prov. (D) (GB) (F) (JAP) (CH) (PL) (B) Jan 6.5 2.6 3.3 5.5 4.2 7.5 4.7 4.9 4.3 6.7 5.5 Feb 7.6 7.2 7.1 7.9 6.6 9.7 8.0 8.3 7.9 9.3 8.6 Mar 8.8 7.7 7.7 7.9 9.8 9.8 8.2 7.5 7.9 9.5 9.5 Apr 15.8 14.7 14.4 17.8 16.5 19.7 16.1 15.5 15.8 17.4 16.8 May 18.5 16.9 16.9 20.5 17.6 23.2 18.8 18.3 16.6 22.2 18.8 Jun 13.1 12.9 13.0 16.2 15.1 17.2 14.7 13.0 14.0 17.3 12.3 Jul 10.5 7.1 7.1 8.9 8.5 12.3 7.1 8.1 7.0 10.3 7.5 Aug 24.7 22.8 23.1 28.2 26.1 29.7 24.8 25.6 24.1 26.9 25.2 Sep 51.3 42.4 41.0 51.3 46.1 52.0 43.6 47.3 44.8 43.9 46.6 Oct 23.3 21.0 21.7 27.2 26.3 29.5 24.0 25.1 23.9 26.3 23.8 Nov 39.3 33.2 33.1 44.7 34.1 42.9 36.5 40.6 35.5 40.0 41.6 Dec 41.5 34.8 35.6 43.8 38.6 44.2 39.6 41.7 42.1 36.8 46.3 SIDC: Sunspot Index Data Center, Brussels (International sunspot numbers) SONNE prov.: SONNE network, provisional sunspot numbers SONNE def.: SONNE network, definitive sunspot numbers AAVSO: American Association of Variable Star Observers - Solar Division AKS: Arbeitskreis Sonne des Kulturbundes e.V., Germany BAA: The British Astronomical Association - Solar Section, UK GFOES: G.F.O.E.S. Commission "Nombre de Wolf", France OAA: The Oriental Astronomical Association - Solar Division, Japan RWG: Rudolf Wolf Gesellschaft - Solar Obs. Group of Swiss Astron. Society TOS: Towarzystwo Obserwatorow Slonca - Solar Observers Society, Poland VVS: Vereniging voor Sterrenkunde, Werkgroep Zon, Belgium