Solar cycle 11

Solar activity from March 1867 to December 1878

Solar cycle 11
Sunspots observed during solar cycle 11 (1873)
Sunspot data
Start date	March 1867
End date	December 1878
Duration (years)	11.8
Max count	234.0
Max count month	August 1870
Min count	9.9
Spotless days	1028
Cycle chronology
Previous cycle	Solar cycle 10 (1855–1867)
Next cycle	Solar cycle 12 (1878–1890)

Solar prominences observed by Carl Frederik Fearnley during solar cycle 11 (1872–1873).

Solar cycle 11 was the eleventh solar cycle since 1755, when extensive recording of solar sunspot activity began.^[1]^[2] The solar cycle lasted 11.8 years, beginning in March 1867 and ending in December 1878. The maximum smoothed sunspot number observed during the solar cycle was 234.0 (August 1870), and the starting minimum was 9.9.^[3] During the minimum transit from solar cycle 11 to 12, there were a total of 1028 days with no sunspots (the highest recorded of any cycle transit to date).^[4]^[5]^[6]

Strong auroral displays were observed in October 1870, February 1872, and August 1872.^[7]

References

^ Kane, R.P. (2002), "Some Implications Using the Group Sunspot Number Reconstruction", Solar Physics, 205 (2): 383–401, Bibcode:2002SoPh..205..383K, doi:10.1023/A:1014296529097
^ "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010.
^ SIDC Monthly Smoothed Sunspot Number. "[1]"
^ Spotless Days. "[2]"
^ Dr. Tony Phillips (11 July 2008). "What's Wrong with the Sun? (Nothing)". NASA. Archived from the original on 14 July 2008.
^ Solaemon's Spotless Days Page. "[3]"
^ Storms, Solar (28 July 2017). "Space Weather Newspaper Archives". www.solarstorms.org.

External links

SIDC formula

Solar cycles

18th century

1740–1759	Solar cycle 1 (1755 Feb – 1766 Jun)
1760–1779	Solar cycle 2 (1766 Jun – 1775 Jun) Solar cycle 3 (1775 Jun – 1784 Sep)
1780–1799	Solar cycle 4 (1784 Sep – 1798 Apr) Solar cycle 5 (1798 Apr – 1810 Aug)

19th century

1800–1819	Solar cycle 6 (1810 Aug – 1823 May)
1820–1839	Solar cycle 7 (1823 May – 1833 Nov) Solar cycle 8 (1833 Nov – 1843 Jul)
1840–1859	Solar cycle 9 (1843 Jul – 1855 Dec) Solar cycle 10 (1855 Dec – 1867 Mar)
1860–1879	Solar cycle 11 (1867 Mar – 1878 Dec) Solar cycle 12 (1878 Dec – 1890 Mar)
1880–1899	Solar cycle 13 (1890 Mar – 1902 Jan)

20th century

1900–1919	Solar cycle 14 (1902 Jan – 1913 Jul) Solar cycle 15 (1913 Jul – 1923 Aug)
1920–1939	Solar cycle 16 (1923 Aug – 1933 Sep) Solar cycle 17 (1933 Sep – 1944 Feb)
1940–1959	Solar cycle 18 (1944 Feb – 1954 Apr) Solar cycle 19 (1954 Apr – 1964 Oct)
1960–1979	Solar cycle 20 (1964 Oct – 1976 Mar) Solar cycle 21 (1976 Mar – 1986 Sep)
1980–1999	Solar cycle 22 (1986 Sep – 1996 Aug) Solar cycle 23 (1996 Aug – 2008 Dec)