889:
29:
500:
842:
866:
818:
854:
830:
356:
178:
Intense red aurora displays frightened people in Europe on 11 February 1958 and were visible from many US cities as far south as the 40th parallel. This geomagnetic storm caused a radio blackout over North
America.
327:
408:
157:
During the minimum transit from solar cycle 19 to 20, there were a total of 227 days with no sunspots. This was the lowest number since 1850.
888:
930:
267:
Dodson, Helen W.; Hedeman, E. Ruth; Mohler, Orren C. (August 1974). "Comparison of activity in solar cycles 18, 19, and 20".
144:
808:
314:
154:
observed during the solar cycle was 285.0, in March 1958 (the highest on record), and the starting minimum was 5.1.
401:
151:
143:
activity began. The solar cycle lasted 10.5 years, beginning in April 1954 and ending in
October 1964. The
923:
949:
394:
331:
169:
in
February 1956 interfered with radio communications and prompted a search for the British submarine
790:
785:
276:
220:
191:
870:
954:
858:
846:
171:
916:
166:
900:
822:
345:
284:
228:
34:
280:
224:
767:
761:
733:
727:
710:
704:
681:
664:
658:
641:
635:
607:
590:
584:
567:
123:
112:
211:
Kane, R.P. (2002), "Some
Implications Using the Group Sunspot Number Reconstruction",
943:
561:
544:
538:
521:
484:
478:
461:
455:
438:
245:
834:
182:
Aurora displays were visible over New York on 13 November 1960 and 1 October 1961.
795:
417:
136:
28:
499:
232:
372:
288:
140:
829:
302:
390:
386:
896:
904:
806:
754:
747:
720:
697:
674:
651:
628:
621:
600:
577:
554:
531:
514:
507:
471:
448:
431:
424:
119:
108:
103:
95:
87:
79:
71:
63:
55:
47:
42:
21:
139:since 1755, when extensive recording of solar
16:Solar activity from April 1954 to October 1964
924:
402:
8:
931:
917:
751:
625:
511:
428:
409:
395:
387:
147:occurred at the peak of this solar cycle.
27:
246:"The Sun: Did You Say the Sun Has Spots?"
813:
301:SIDC Monthly Smoothed Sunspot Number. "
203:
328:"What's Wrong with the Sun? (Nothing)"
37:during solar cycle 19 (11 April 1959).
18:
7:
885:
883:
903:. You can help Knowledge (XXG) by
373:"Space Weather Newspaper Archives"
326:Dr. Tony Phillips (11 July 2008).
14:
887:
864:
852:
840:
828:
816:
498:
344:Solaemon's Spotless Days Page. "
796:List of solar maxima and minima
371:Storms, Solar (28 July 2017).
145:International Geophysical Year
1:
175:after it lost radio contact.
895:This article related to the
971:
882:
358:Amsterdam Evening Recorder
781:
496:
26:
289:10.1029/RG012i003p00329
233:10.1023/A:1014296529097
152:smoothed sunspot number
330:. NASA. Archived from
764:(2008 Dec – 2019 Dec)
736:(1996 Aug – 2008 Dec)
730:(1986 Sep – 1996 Aug)
713:(1976 Mar – 1986 Sep)
707:(1964 Oct – 1976 Mar)
690:(1954 Apr – 1964 Oct)
684:(1944 Feb – 1954 Apr)
667:(1933 Sep – 1944 Feb)
661:(1923 Aug – 1933 Sep)
644:(1913 Jul – 1923 Aug)
638:(1902 Jan – 1913 Jul)
610:(1890 Mar – 1902 Jan)
593:(1878 Dec – 1890 Mar)
587:(1867 Mar – 1878 Dec)
570:(1855 Dec – 1867 Mar)
564:(1843 Jul – 1855 Dec)
547:(1833 Nov – 1843 Jul)
541:(1823 May – 1833 Nov)
524:(1810 Aug – 1823 May)
487:(1798 Apr – 1810 Aug)
481:(1784 Sep – 1798 Apr)
464:(1775 Jun – 1784 Sep)
458:(1766 Jun – 1775 Jun)
441:(1755 Feb – 1766 Jun)
269:Reviews of Geophysics
791:List of solar storms
786:List of solar cycles
770:(2019 Dec – present)
248:. Space Today Online
192:List of solar cycles
377:www.solarstorms.org
281:1974RvGSP..12..329D
225:2002SoPh..205..383K
135:was the nineteenth
360:, 24 February 1956
912:
911:
804:
803:
777:
776:
743:
742:
617:
616:
494:
493:
167:geomagnetic storm
130:
129:
962:
933:
926:
919:
891:
884:
869:
868:
867:
857:
856:
855:
845:
844:
843:
833:
832:
821:
820:
819:
812:
752:
626:
512:
502:
429:
411:
404:
397:
388:
381:
380:
368:
362:
354:
348:
342:
336:
335:
334:on 14 July 2008.
323:
317:
313:Spotless Days. "
311:
305:
299:
293:
292:
264:
258:
257:
255:
253:
242:
236:
235:
208:
104:Cycle chronology
64:Duration (years)
35:solar prominence
31:
19:
970:
969:
965:
964:
963:
961:
960:
959:
940:
939:
938:
937:
880:
877:
875:
865:
863:
853:
851:
841:
839:
827:
817:
815:
807:
805:
800:
773:
768:Solar cycle 25
762:Solar cycle 24
739:
734:Solar cycle 23
728:Solar cycle 22
716:
711:Solar cycle 21
705:Solar cycle 20
693:
688:Solar cycle 19
682:Solar cycle 18
670:
665:Solar cycle 17
659:Solar cycle 16
647:
642:Solar cycle 15
636:Solar cycle 14
613:
608:Solar cycle 13
596:
591:Solar cycle 12
585:Solar cycle 11
573:
568:Solar cycle 10
550:
527:
503:
490:
467:
444:
420:
415:
385:
384:
370:
369:
365:
355:
351:
343:
339:
325:
324:
320:
312:
308:
300:
296:
266:
265:
261:
251:
249:
244:
243:
239:
210:
209:
205:
200:
188:
163:
80:Max count month
38:
17:
12:
11:
5:
968:
966:
958:
957:
952:
942:
941:
936:
935:
928:
921:
913:
910:
909:
892:
874:
873:
861:
849:
837:
825:
802:
801:
799:
798:
793:
788:
782:
779:
778:
775:
774:
772:
771:
765:
758:
756:
749:
745:
744:
741:
740:
738:
737:
731:
724:
722:
718:
717:
715:
714:
708:
701:
699:
695:
694:
692:
691:
685:
678:
676:
672:
671:
669:
668:
662:
655:
653:
649:
648:
646:
645:
639:
632:
630:
623:
619:
618:
615:
614:
612:
611:
604:
602:
598:
597:
595:
594:
588:
581:
579:
575:
574:
572:
571:
565:
562:Solar cycle 9
558:
556:
552:
551:
549:
548:
545:Solar cycle 8
542:
539:Solar cycle 7
535:
533:
529:
528:
526:
525:
522:Solar cycle 6
518:
516:
509:
505:
504:
497:
495:
492:
491:
489:
488:
485:Solar cycle 5
482:
479:Solar cycle 4
475:
473:
469:
468:
466:
465:
462:Solar cycle 3
459:
456:Solar cycle 2
452:
450:
446:
445:
443:
442:
439:Solar cycle 1
435:
433:
426:
422:
421:
416:
414:
413:
406:
399:
391:
383:
382:
363:
349:
337:
318:
306:
294:
275:(3): 329–341.
259:
237:
219:(2): 383–401,
202:
201:
199:
196:
195:
194:
187:
184:
162:
161:Extreme events
159:
133:Solar cycle 19
128:
127:
124:Solar cycle 20
121:
117:
116:
113:Solar cycle 18
110:
109:Previous cycle
106:
105:
101:
100:
97:
93:
92:
89:
85:
84:
81:
77:
76:
73:
69:
68:
65:
61:
60:
57:
53:
52:
49:
45:
44:
40:
39:
32:
24:
23:
22:Solar cycle 19
15:
13:
10:
9:
6:
4:
3:
2:
967:
956:
953:
951:
948:
947:
945:
934:
929:
927:
922:
920:
915:
914:
908:
906:
902:
898:
893:
890:
886:
881:
878:
872:
862:
860:
850:
848:
838:
836:
831:
826:
824:
814:
810:
797:
794:
792:
789:
787:
784:
783:
780:
769:
766:
763:
760:
759:
757:
753:
750:
746:
735:
732:
729:
726:
725:
723:
719:
712:
709:
706:
703:
702:
700:
696:
689:
686:
683:
680:
679:
677:
673:
666:
663:
660:
657:
656:
654:
650:
643:
640:
637:
634:
633:
631:
627:
624:
620:
609:
606:
605:
603:
599:
592:
589:
586:
583:
582:
580:
576:
569:
566:
563:
560:
559:
557:
553:
546:
543:
540:
537:
536:
534:
530:
523:
520:
519:
517:
513:
510:
506:
501:
486:
483:
480:
477:
476:
474:
470:
463:
460:
457:
454:
453:
451:
447:
440:
437:
436:
434:
430:
427:
423:
419:
412:
407:
405:
400:
398:
393:
392:
389:
378:
374:
367:
364:
361:
359:
353:
350:
346:
341:
338:
333:
329:
322:
319:
315:
310:
307:
303:
298:
295:
290:
286:
282:
278:
274:
270:
263:
260:
247:
241:
238:
234:
230:
226:
222:
218:
214:
213:Solar Physics
207:
204:
197:
193:
190:
189:
185:
183:
180:
176:
174:
173:
168:
160:
158:
155:
153:
148:
146:
142:
138:
134:
125:
122:
118:
114:
111:
107:
102:
98:
96:Spotless days
94:
90:
86:
82:
78:
74:
70:
66:
62:
58:
54:
50:
46:
41:
36:
30:
25:
20:
950:Solar cycles
905:expanding it
894:
879:
876:
871:Solar System
748:21st century
687:
622:20th century
508:19th century
425:18th century
418:Solar cycles
376:
366:
357:
352:
340:
332:the original
321:
309:
297:
272:
268:
262:
250:. Retrieved
240:
216:
212:
206:
181:
177:
170:
164:
156:
150:The maximum
149:
132:
131:
59:October 1964
43:Sunspot data
859:Outer space
847:Spaceflight
137:solar cycle
126:(1964–1976)
115:(1944–1954)
944:Categories
198:References
120:Next cycle
83:March 1958
51:April 1954
48:Start date
955:Sun stubs
823:Astronomy
755:2000–2019
721:1980–1999
698:1960–1979
675:1940–1959
652:1920–1939
629:1900–1919
601:1880–1899
578:1860–1879
555:1840–1859
532:1820–1839
515:1800–1819
472:1780–1799
449:1760–1779
432:1740–1759
252:12 August
88:Min count
72:Max count
186:See also
56:End date
809:Portals
277:Bibcode
221:Bibcode
172:Acheron
141:sunspot
899:is a
835:Stars
75:285.0
901:stub
254:2010
67:10.5
897:Sun
285:doi
229:doi
217:205
99:227
91:5.1
946::
375:.
283:.
273:12
271:.
227:,
215:,
165:A
33:A
932:e
925:t
918:v
907:.
811::
410:e
403:t
396:v
379:.
347:"
316:"
304:"
291:.
287::
279::
256:.
231::
223::
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
