Solar cycle 10

Solar cycle 10 was the tenth solar cycle since 1755, when extensive recording of solar sunspot activity began.[1][2] The solar cycle lasted 11.3 years, beginning in December 1855 and ending in March 1867. The maximum smoothed sunspot number (SIDC formula) observed during the solar cycle was 186.2 (February 1860), and the starting minimum was 6.0.[3] During the transit from solar cycle 10 to 11, there were a total of 406 days with no sunspots.[4][5][6]

Solar cycle 10
Sunspots during solar cycle 10, as sketched by Richard Carrington (September 1, 1859).
Sunspot data
Start date	December 1855
End date	March 1867
Duration (years)	11.3
Max count	186.2
Max count month	February 1860
Min count	6.0
Spotless days	406
Cycle chronology
Previous cycle	Solar cycle 9 (1843-1855)
Next cycle	Solar cycle 11 (1867-1878)

The first observations of solar flares, by Richard Carrington and Richard Hodgson (independently), occurred during this cycle.[7]

Solar storm of 1859

On September 1–2, 1859, the largest recorded geomagnetic storm on Earth occurred, known as the Carrington Event.[7][8] Aurorae were seen around the world, even over the Caribbean; those over the Rocky Mountains were so bright that their glow awoke gold miners, who began preparing breakfast because they thought it was morning.[9]

Telegraph systems all over Europe and North America failed.[10] Telegraph pylons threw sparks and telegraph paper spontaneously caught fire. Some telegraph systems appeared to continue to send and receive messages despite having been disconnected from their power supplies.

From August 28, 1859 until September 2, numerous sunspots and solar flares were observed on the sun. Just before noon on September 1, the British astronomer Richard Carrington observed the largest flare, which would later be named after him.[7]

See also

• Solar variation
• List of solar cycles

References

1. Kane, R.P. (2002). "Some Implications Using the Group Sunspot Number Reconstruction". Solar Physics 205(2), 383-401.
2. "The Sun: Did You Say the Sun Has Spots?". Space Today Online. Retrieved 12 August 2010.
3. SIDC Monthly Smoothed Sunspot Number. ""
4. Spotless Days. ""
5. What's Wrong with the Sun? (Nothing) more information: Spotless Days. ""Archived copy". Archived from the original on 2008-07-14. Retrieved 2017-07-12.CS1 maint: archived copy as title (link)"
6. Solaemon's Spotless Days Page. ""
7. Odenwald, Sten F.; Green, James L. (28 July 2008). "Bracing the Satellite Infrastructure for a Solar Superstorm". Scientific American. Retrieved 4 April 2018.
8. "NASA — Severe Space Weather".
9. "Timeline: The 1859 Solar Superstorm".
10. "The Great Storm: Solar Tempest of 1859 Revealed".