A Sunspot from Cycle 25 for sure

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|publish_date = 10 April 2018
|publish_date = 10 April 2018
|next_nugget={{#ask: [[Category:Nugget]] [[RHESSI Nugget Index::322]]}}
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|previous_nugget=[http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Blue-wing_enhancement_of_the_Mg_II_h_and_k_lines_in_a_flare Blue-wing evaporation]
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|previous_nugget={{#ask: [[Category:Nugget]] [[RHESSI Nugget Index::320]]}}
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This brief Nugget simply announces that YES, we really have seen  
This brief Nugget simply announces that YES, we really have seen  
[https://en.wikipedia.org/wiki/Solar_cycle_25 Cycle 25]
[https://en.wikipedia.org/wiki/Solar_cycle_25 Cycle 25]
-
[sunspot activity].
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[http://www.scholarpedia.org/article/Solar_activity sunspot activity].
An [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/A_Curious_Sunspot_Group_in_2018 earlier Nugget]  
An [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/A_Curious_Sunspot_Group_in_2018 earlier Nugget]  
hinted at this, but it was not so clear a case as presented by today's
hinted at this, but it was not so clear a case as presented by today's
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[https://en.wikipedia.org/wiki/Stochastic stochastic] component of the  
[https://en.wikipedia.org/wiki/Stochastic stochastic] component of the  
development of the
development of the
-
[https://solarscience.msfc.nasa.gov/SunspotCycle.shtml solar magnetic cycle].  
+
[https://solarscience.msfc.nasa.gov/SunspotCycle.shtml solar magnetic cycle].
== The Cycle 25 Sunspot ==
== The Cycle 25 Sunspot ==
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The icon for this Nugget on the parent page here has a slightly better  
The icon for this Nugget on the parent page here has a slightly better  
view derived from a 4096x4096 image.
view derived from a 4096x4096 image.
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 +
== And a flare! ==
 +
 +
Sam Freeland notes that this little region arguably has produced the
 +
[http://sdowww.lmsal.com/sdomedia/ssw/media/ssw/ssw_client/data/ssw_service_180409_152748_17806_2/www/ first flare of Cycle 25].
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We might label this SOL2018-04-09T12:57 (A2.5).
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We thank  Bill Marquette and Dick Canfield for relaying this information.
 +
Could such a tiny event have been detected by GOES at the corresponding phase of the previous cycle?
== Conclusion ==
== Conclusion ==
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The Nugget-writers here thank him for his thorough monitoring of solar
The Nugget-writers here thank him for his thorough monitoring of solar
activity, and also thank Leif Svalgaard for paying close attention as well.
activity, and also thank Leif Svalgaard for paying close attention as well.
 +
 +
[[Has observation by:: SDO HMI| ]]

Latest revision as of 11:32, 18 September 2018


Nugget
Number: 321
1st Author: Tomek Mrozek
2nd Author: Hugh Hudson
Published: 10 April 2018
Next Nugget: Observation of Cosmic Ray Spallation Events from SoHO
Previous Nugget: Blue-wing enhancement of the Mg II h and k lines in a flare
List all



Contents

Introduction

This brief Nugget simply announces that YES, we really have seen Cycle 25 sunspot activity. An earlier Nugget hinted at this, but it was not so clear a case as presented by today's new tiny sunspot. Why is this interesting? It's because spots appearing this early in a cycle - even before a minimum is well established - are quite rare. We could speculate that solar minimum may arrive early and/or may be brief, more evidence regarding the seemingly stochastic component of the development of the solar magnetic cycle.

The Cycle 25 Sunspot

At the time of writing, NOAA has not identified this new sunspot with an official active-region number, and so there could be some things to quibble about. But the magnetic polarity of the region unmistakeably identifies it as a piece of the new cycle, because it reverses the polarity expected for Cycle 24 regions.

Figure 1 here shows the new spot as of this date (10-April-2018). It is marginally detectable but definitely there in relatively crude 1024x1025 .gif versions of the beautiful data from the SDO space observatory.

Figure 1: File images from the HMI instrument on SDO: left, the continuum intensity; right, the telltale magnetic field. From the latter one can see black polarity to the right ("preceding", as the Sun rotates). This is the opposite of that shown, for example, by the exceedingly tiny region at about -5 degrees.

It requires a bit of patience to see the spot; refer to the location of the magnetic features and perhaps dither the window on your browser screen. The icon for this Nugget on the parent page here has a slightly better view derived from a 4096x4096 image.

And a flare!

Sam Freeland notes that this little region arguably has produced the first flare of Cycle 25. We might label this SOL2018-04-09T12:57 (A2.5). We thank Bill Marquette and Dick Canfield for relaying this information. Could such a tiny event have been detected by GOES at the corresponding phase of the previous cycle?

Conclusion

This sunspot has been tabulated in the excellent SOLEN page of Jan Alvestad. The Nugget-writers here thank him for his thorough monitoring of solar activity, and also thank Leif Svalgaard for paying close attention as well.


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