At a minimum, there are no sunspots at all, and the Sun can remain spotless for months at a time. In 2009, for example, there were 260 spotless days. In 2008, there had been 200 spotless days - by September! This last solar minimum lasted for about 18 months longer than is "normal", whatever "normal" is. Since December 2009, the Sun has slowly become more and more active, with at least a few sunspots visible almost every day since then.
The Solar Maximum in 2004 was QUITE active; the Sun looked freckled!
The number of sunspots varies from day to day, and even from hour to hour, as new spots develop and old ones fade away or are carried around the Sun as it turns. And big sunspots count for more than little ones do.
NASA calculates a "sunspot number" each day as a measure of the solar activity. This isn't the number of spots, but is calculated based on the total area of all the sunspots.
Today, the sunspot number is zero; there are no spots on the Sun at all. The Sun has been in an extended minimum, and there have been very few spots for the past few years. But at the solar maximum, the sunspot number is 400, or 500 or even higher.
You can see the sunspot number each day at spaceweather.com.
It is when the sun spots increase until maximum
200
Noone knows for sure how many there are. Currently, it is in a solar maximum which is a stage after a solar flare which is the biggest explosion that can occur in space, During a solar maximum sunspots develop. so the numbers keep growing
On average, each sunspot cycle takes about 11 years. Some are longer, and some shorter.
The last Solar Maximum was in 2002. The Sun is currently at the minimum of the sunspot cycle, perhaps just at the beginning of the new Cycle 24. So far, the Sunspot Number for February is Zero - no sunspots at all this month so far (as of February 8, 2009). You can check the sunspot number, and see fascinating things about things in space each day at www.spaceweather.com. It is currently focusing on photos of Comet Lulin, the Green Comet. _________________________________ The problem with WikiAnswers is that if you ask a question that is time-related, such as "When was the last sunspot maximum?", the answer becomes less and less useful as time goes by. The answer above was from February, 2009; today is April 10, 2014, five years later. The "last sunspot maximum" answer now would be "last month", since we're at or near the Solar Max. It's been a long time coming; the last solar cycle dawdled for a year longer than it should have, and this cycle looks like it's going to be well below the average of previous solar cycles. But the spaceweather.com website, linked below, is still the best resource for questions like this.
Sunspots are cold because there is no light or heat reaching them from the sun and they experience supreme convection which reduces the surface temerature.
Magnetic fields that dot the surface of the sun are known as sunspots. Although they are hardly cool in temperature, they are much colder than surrounding areas, which causes them to be visible as darkened spots.
Noone knows for sure how many there are. Currently, it is in a solar maximum which is a stage after a solar flare which is the biggest explosion that can occur in space, During a solar maximum sunspots develop. so the numbers keep growing
On average, each sunspot cycle takes about 11 years. Some are longer, and some shorter.
Sunspots appear pretty much all the time, but there are more of them during a solar maximum.
Experts are still debating this question. There were no sunspots observed on 266 of 2008's 366 days (73%). To find a year with more blank suns, you have to go all the way back to 1913, which had 311 spotless days. Prompted by these numbers, some observers suggested that the solar cycle had hit bottom in 2008. Maybe not. Sunspot counts for 2009 have dropped even lower. As of March 31st, there were no sunspots on 78 of the year's 90 days (87%). It adds up to one inescapable conclusion: "We're experiencing a very deep solar minimum," says solar physicist Dean Pesnell of the Goddard Space Flight Center. "This is the quietest sun we've seen in almost a century," agrees sunspot expert David Hathaway of the Marshall Space Flight Center. Quiet suns come along every 11 years or so. It's a natural part of the sunspot cycle, discovered by German astronomer Heinrich Schwabe in the mid-1800s. Sunspots are planet-sized islands of magnetism on the surface of the sun; they are sources of solar flares, coronal mass ejections and intense UV radiation. Plotting sunspot counts, Schwabe saw that peaks of solar activity were always followed by valleys of relative calm-a clockwork pattern that has held true for more than 200 years. _________________________ Update: The quiet period of Solar Cycle 23 ended in December, 2009, and we can now (July 29,2011) see that Solar Cycle 24 is proceeding pretty much as expected. During 2010, there were 51 spotless days; so far in 2011, there has been ONE. You can see today's Sun and the sunspot number at spaceweather.com.
Suspots don't actually MOVE across the face of the Sun; a sunspot pretty much stays put. So when we see sunspots APPEAR to move, what we're actually seeing is the rotation of the Sun itself.
The last Solar Maximum was in 2002. The Sun is currently at the minimum of the sunspot cycle, perhaps just at the beginning of the new Cycle 24. So far, the Sunspot Number for February is Zero - no sunspots at all this month so far (as of February 8, 2009). You can check the sunspot number, and see fascinating things about things in space each day at www.spaceweather.com. It is currently focusing on photos of Comet Lulin, the Green Comet. _________________________________ The problem with WikiAnswers is that if you ask a question that is time-related, such as "When was the last sunspot maximum?", the answer becomes less and less useful as time goes by. The answer above was from February, 2009; today is April 10, 2014, five years later. The "last sunspot maximum" answer now would be "last month", since we're at or near the Solar Max. It's been a long time coming; the last solar cycle dawdled for a year longer than it should have, and this cycle looks like it's going to be well below the average of previous solar cycles. But the spaceweather.com website, linked below, is still the best resource for questions like this.
Sunspots are cold because there is no light or heat reaching them from the sun and they experience supreme convection which reduces the surface temerature.
Sunspots are regions on the solar surface that appear dark because they are cooler than the surrounding photosphere, typically by about 1500 K (thus, they are still at a temperature of about 4500 K, but this is cool compared to the rest of the photosphere). They are only dark in a relative sense; a sunspot removed from the bright background of the Sun would glow quite brightly. Some sunspots are as large as 50,000 miles across, and they move across the surface of the sun, contracting and expanding as they go. The sun has a magnetic field that is twisted around inside the Sun as it spins. There are places on the sun where this magnetic field rises up from below the sun's surface and pokes through, creating sunspots. Sunspots are magnetic and often have a north and south pole like a magnet. They come and go over the surface of the Sun and last from a few days to a few weeks. The period of time between maximum outbreaks of sunspots is about 9 to 14 years, with an average of 11 years. A link can be found below.
The sun don't really need sunspots cause sunspots are related to several features on the sun's surface but prominences and solar flares need sunspots.Sunspots are the places where the magnetic field lines of the Sun poke out of the Sun to form loops.Where they poke out they are seens as prominences against the edge of the Sun's visible disk during an eclipse of the Sun.The looped magnetic field lines contain energy and are unstable, When they break and reconnect they release this energy suddenly and cause solar flares.
The sun spins faster at the equator then at the poles, this causes a difference in magnetic fields. Once one is looped, the temperature of the area will decrease, causing a sun spotSunspots are caused by the intense magnetic field of the sun, they usually occur the most during the high peak of the solar cycle.
Nothing Much.
Because the sunspots are cooler spots on the sun. They are much different from the rest of the sun so the appear really dark.