Posted on Sep 17, 2020
APOD: 2020 September 17 - Solar Cycle 25 Begins
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Good morning, Rallypoint. Today's Astronomy Picture of the Day (APOD) is titled "Solar Cycle 25 Begins." How do we know when a solar cycle begins or ends? By the number of sunspots. Based on data going back to February 1755, sunspots appear and disappear in a periodic cycle of about 11 years.
Galileo Galilei, Christoph Scheiner and their contemporaries conducted the first systematic study of sunspots in the early 1600s. In 1775, Christian Horrebow first suggested a 'solar cycle' based on observations he conducted beginning in 1761 at the observatory Rundetaarn in Copenhagen. Discovery of the solar cycle is credited to Samuel Heinrich Schwabe, who after 17 years of observations noticed a periodic variation in the average number of sunspots and published his results in 1843. Rudolf Wolf compiled and studied these and other observations, reconstructing the cycle back to 1745, eventually pushing these reconstructions to the earliest observations of sunspots by Galileo and contemporaries in the early seventeenth century.
Wolf also created a numbering scheme (the "Wolf Index") to identify solar cycles and their annual sunspot count. Following this approach, the 1755–1766 solar cycle is traditionally numbered "1". Based on the Wolf Index, the general trend of monthly sunspot data now confirms that the minimum of the approximately 11 year cycle of solar activity occurred in December 2019. This marks the start of Solar Cycle 25. Today's APOD shows a quiet Sun (at minimum activity) on the right of this composite hemispherical view. In contrast, the left side shows the active Sun in April 2014 at the recognized maximum of Solar Cycle 24.
Galileo Galilei, Christoph Scheiner and their contemporaries conducted the first systematic study of sunspots in the early 1600s. In 1775, Christian Horrebow first suggested a 'solar cycle' based on observations he conducted beginning in 1761 at the observatory Rundetaarn in Copenhagen. Discovery of the solar cycle is credited to Samuel Heinrich Schwabe, who after 17 years of observations noticed a periodic variation in the average number of sunspots and published his results in 1843. Rudolf Wolf compiled and studied these and other observations, reconstructing the cycle back to 1745, eventually pushing these reconstructions to the earliest observations of sunspots by Galileo and contemporaries in the early seventeenth century.
Wolf also created a numbering scheme (the "Wolf Index") to identify solar cycles and their annual sunspot count. Following this approach, the 1755–1766 solar cycle is traditionally numbered "1". Based on the Wolf Index, the general trend of monthly sunspot data now confirms that the minimum of the approximately 11 year cycle of solar activity occurred in December 2019. This marks the start of Solar Cycle 25. Today's APOD shows a quiet Sun (at minimum activity) on the right of this composite hemispherical view. In contrast, the left side shows the active Sun in April 2014 at the recognized maximum of Solar Cycle 24.
APOD: 2020 September 17 - Solar Cycle 25 Begins
Posted from apod.nasa.gov
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They apparently have a huge impact on our weather
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SGT Denny Espinosa
>1 y
I remember buying my first CB radio and being warned about the 11-year cycle because it would scramble the broadcast.
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Lt Col John (Jack) Christensen
>1 y
More than just weather, I can remember them messing up low frequency radio from my B-52 days.
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Brandon Bee - Radiant Sun (Give Thanks to the One) (Live)
Brandon Bee Live @BethelFamily in El Paso, TX
Thank you my friend Maj William W. 'Bill' Price for posting the NASA Astronomy Picture of the Day (APOD) for Thursday, September 17, 2020 entitled "Solar Cycle 25 Begins."
Thanks for posting an amazing dual image. This golden image reminds of the gold standard from long ago.
Image: Solar Cycle 25 Has Begun - Image Credit - NASA, SDO
APOD Background
"Explanation: The general trend of monthly sunspot data now confirms that the minimum of the approximately 11 year cycle of solar activity occurred in December 2019, marking the start of Solar Cycle 25. That quiet Sun, at minimum activity, appears on the right of this split hemispherical view. In contrast, the left side shows the active Sun at the recognized maximum of Solar Cycle 24, captured in April 2014. The extreme ultraviolet images from the orbiting Solar Dynamics Observatory highlight coronal loops and active regions in the light of highly ionized iron atoms. Driving the space weather around our fair planet, Solar Cycle 24 was a relatively calm one and predictions are that cycle 25 will be calm too. The cycle 25 activity maximum is expected in July 2025. Solar Cycle 1, the first solar cycle determined from early records of sunspot data, is considered to begin with a minimum in February 1755."
Brandon Bee - Radiant Sun (Give Thanks to the One) (Live)
https://www.youtube.com/watch?v=FfhU47XONNQ
FYI Maj Robert Thornton Lt Col Charlie Brown COL Mikel J. Burroughs Sgt (Join to see) PO1 William "Chip" Nagel Maj Bill Smith, Ph.D. Lt Col John (Jack) Christensen SGT Denny Espinosa Sgt Vance Bonds MAJ Dale E. Wilson, Ph.D. TSgt David L. SPC Nancy GreenePO2 (Join to see) SSG Michael Noll SGT Denny Espinosa SPC Margaret Higgins Maj Marty Hogan TSgt Joe C.
Thanks for posting an amazing dual image. This golden image reminds of the gold standard from long ago.
Image: Solar Cycle 25 Has Begun - Image Credit - NASA, SDO
APOD Background
"Explanation: The general trend of monthly sunspot data now confirms that the minimum of the approximately 11 year cycle of solar activity occurred in December 2019, marking the start of Solar Cycle 25. That quiet Sun, at minimum activity, appears on the right of this split hemispherical view. In contrast, the left side shows the active Sun at the recognized maximum of Solar Cycle 24, captured in April 2014. The extreme ultraviolet images from the orbiting Solar Dynamics Observatory highlight coronal loops and active regions in the light of highly ionized iron atoms. Driving the space weather around our fair planet, Solar Cycle 24 was a relatively calm one and predictions are that cycle 25 will be calm too. The cycle 25 activity maximum is expected in July 2025. Solar Cycle 1, the first solar cycle determined from early records of sunspot data, is considered to begin with a minimum in February 1755."
Brandon Bee - Radiant Sun (Give Thanks to the One) (Live)
https://www.youtube.com/watch?v=FfhU47XONNQ
FYI Maj Robert Thornton Lt Col Charlie Brown COL Mikel J. Burroughs Sgt (Join to see) PO1 William "Chip" Nagel Maj Bill Smith, Ph.D. Lt Col John (Jack) Christensen SGT Denny Espinosa Sgt Vance Bonds MAJ Dale E. Wilson, Ph.D. TSgt David L. SPC Nancy GreenePO2 (Join to see) SSG Michael Noll SGT Denny Espinosa SPC Margaret Higgins Maj Marty Hogan TSgt Joe C.
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LTC Stephen F.
>1 y
Provided to YouTube by CDBaby Radiant Sun · Molly Sweeney Gold Rings and Fur Pelts 2011 M. Sweeney Released on: 2011-06-07 Auto-generated by YouTube.
Radiant Sun · Molly Sweeney
https://www.youtube.com/watch?v=a_8US0NAY3k
FYI MSG Felipe De Leon Brown PO3 Phyllis MaynardSSG Franklin BriantPO1 Robert GeorgeMSG Felipe De Leon Brown Sgt John H. CW5 Jack Cardwell SGT David A. 'Cowboy' Groth SGT (Join to see) SMSgt Dr. G. A. ThomasSSgt Marian MitchellSSG Jeffrey LeakePFC (Join to see)SP5 Dennis LobergerSGT Michael Hearn1619267:SPC Michael Duricko-phd] SFC (Join to see) Capt Dwayne Conyers PO1 William "Chip" Nagel
https://www.youtube.com/watch?v=a_8US0NAY3k
FYI MSG Felipe De Leon Brown PO3 Phyllis MaynardSSG Franklin BriantPO1 Robert GeorgeMSG Felipe De Leon Brown Sgt John H. CW5 Jack Cardwell SGT David A. 'Cowboy' Groth SGT (Join to see) SMSgt Dr. G. A. ThomasSSgt Marian MitchellSSG Jeffrey LeakePFC (Join to see)SP5 Dennis LobergerSGT Michael Hearn1619267:SPC Michael Duricko-phd] SFC (Join to see) Capt Dwayne Conyers PO1 William "Chip" Nagel
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