For the last few days, telescopes aimed at the sun have detected very few sunspots experiencing an unusual phenomenon dubbed a "Big Quiet".
The event marks the absence of sunspots during what is supposed to be a heightened period of magnetic activity on our sun, which Swinburne University astrophysicist Dr Alan Duffy called a "very weird" development.
"Sunspots can change all the time, but when you should be seeing many dozens at any one point of time, it's quite strange that we're not seeing any at all," Duffy told the Sydney Morning Herald. "We don't have any idea why that is."
Sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots, compared to surrounding regions.
They are the region of the sun where solar activity originates when material is ejected into space following solar flares, sudden flashes of brightness and coronal mass ejections (CMEs).
Sunspots appear darker to us as they are caused by highly concentrated magnetic fields that are slightly cooler than the surrounding surface of the sun. Solar flares and CMEs occur when built-up energy is released.
The spots are one gauge of a solar cycle, an approximately 11-year period of above average or below average magnetic activity. Currently, the sun is in a maximum period, so observations of sunspots and solar flares should be more common.
Yet an image taken by Nasa's Solar Dynamics Observatory shows a distinct absence of sunspots, with just a small dot of brown just right of the centre where a small sunspot appears to be developing.
Speaking to the LA Times, physicist Tony Phillips, who writes about solar activity on his website Spaceweather.com, said it was not altogether that usual to have a Big Quiet event.
"It is weird, but it's not super weird," said Phillips. "To have a spotless day during solar maximum is odd, but then again, this solar maximum we are in has been very wimpy."
Phillips explained that we were currently in the weakest solar maximum to have been observed in the space age, so a spotless sun was not all that uncommon.
"It all underlines that solar physicists really don't know what the heck is happening on the sun," Phillips said. "We just don't know how to predict the sun, that is the take away message of this event."
The Sun seems to have given itself a few days off.
As noted by the Solar Dynamics Observatory, with reference to data from the Royal Observatory of Belgium's Sunspot Index and Long-term Solar Observations (SILSO) project, last Thursday July 17th saw the Sun produce no sunspots.
That's the first sunspot-free day since 2011. And as the graph below shows, Sol seems to be having a bit of a rest at present.
Before you rush to any conclusions about what this all might mean for the state of the Sun's climate, or Earth's, here's SILSO's longer-term look at sunspot activity.This graph shows a trend towards a dip, but also that low sunspot activity has recently been observed.
originally posted by: Skywatcher2011
I find this subject interesting because it is an event that you don't hear about too often. Why does the sun take certain intermissions like this? Why don't we see this on a more frequent occurrence?
I am not a true expert on this matter...but my questions to this event are:
Do sun spots block excess heat coming to Earth?
If so...then will a spotless sun increase the average temperatures on Earth?
originally posted by: Vasa Croe
The calm before the storm comes to mind. Just recharging before the kill shot......
The maunder minimum seemed to have some correlation to lower temperatures in Europe as did the other minimums of sunspot activity, but whether this was representative of global temperature isn't certain. The time scale of your graph is a lot longer and I don't even see the maunder minimum on it.
originally posted by: engvbany
In the long term, no correlation between sunspot numbers and climate ...
Like the Dalton Minimum and Spörer Minimum, the Maunder Minimum coincided with a period of lower-than-average European temperatures...
The Maunder Minimum coincided with the middle part of the Little Ice Age, during which Europe and North America were subjected to very cold winters.
2014 Update: In the first quarter of 2014, the Sun starting heating up. February 2014 averaged 102.8 spots a day, which is the first time the cycle broke 100. March 2014 was also very high with 92.2 spots a day. More importantly, March set a record sunspot peak of 73.2 for Cycle 24 (versus the 68.9 record peak in February). In the second quarter of 2014, the sunspot number continues to rise toward a second peak and has now surpassed the first peak (February of 2012). Many cycles are double-peaked but this is unusual in that the second peak is larger than the first.