Is Our Sun Slowing Down in Its Middle Age?

By: Monica Bobra writing in Sky and Telescope

The Sun, now halfway through its life, might be slowing its magnetic activity, researchers say, which could lead to permanent changes in the sunspots and auroras we see.

We all slow down in middle age, has our sun reached that point?

There is evidence that Sun-like stars slow their magnetic activity after reaching middle age. And the Sun is, in fact, at just that age. But while we might be seeing some evidence of a slow-down, the process will likely happen over thousands, if not millions, of years. Furthermore, this is not the first time that the Sun has deviated from previous behavior. During a 70-year period in the 17th century, the Sun shed all but a few of its sunspots, only to right its course again.

Well maybe not! It could just be another overlapping cycle.

And maybe we’re not seeing a slow-down at all. While the strongest sunspot cycle rises and falls over the course of 11 years, there are other sunspot cycles that rise and fall over longer timespans. These other cycles could affect the 11-year cycle. So we can’t yet conclude that the Sun’s relatively recent changes are permanent. The best thing to do is just keep on looking: There are many more clues buried in the Sun’s many heartbeats.

I write about some of those cycles in a paper on the Dalton Minimum. dalton_minimum

Here is a chart from that paper showing the multiple solar cycles:

Solar Cycles

Your thoughts?  Middle age sun, or just another cycle?


5 thoughts on “Is Our Sun Slowing Down in Its Middle Age?

  1. TinyCO2 July 22, 2017 / 3:59 pm

    I’ve always wondered if the Earth’s climate has a signal from the Sun that we’ve never been around to measure or even had the equipment to see. Our slow transformation in the last 3 million years from a no glacial cycle to a 41k year cyle to a 100k year cycle, may have come partly from what the Sun was doing. Perhaps the reason we aren’t in a glaciation period is because the Sun isn’t giving the signal for it? What if a quiet Sun was normal and we were set for a hundred tousand years of Dalton Minimums? Or something even more odd?

  2. Gabriel July 22, 2017 / 4:06 pm

    According to a report posted by Bruce Dorminey, a Forbes contributor, in June 27th, 2016, Astronomer Travis Metcalfe (from Space Science Institute – Boulder, Colorado) et al. published a paper in ‘The Astrophysical Journal Letters’ which refers the Sun is currently in a special phase of its magnetic evolution. The Sun might be right in the middle of its magnetic middle age, in a transition to a state it will have less sunspots than in the first half of its 10-billion years life. This phase will end with the Sun showing no sunspots at all like any other M-spectral class star. The whole transition process shall take millions of years to be completed. Nevertheless, for now the Sun may have entered a long-term period of magnetic inactivity. The study was accomplished with the use of Kepler Space Telescope.

    • Russ Steele July 27, 2017 / 8:30 pm

      Hi Gabriel,
      Do you have a link to the study?

  3. geo Germain July 23, 2017 / 11:35 am

    Hi Russ, interesting thoughts. I imagined the solar cycles effects in the same way as the Earth tides affected mainly by the moon and sun. If these nearby bodies affect the tides this way, then maybe the planets also affect the sun in a similar way. Then, each planet would contribute to the gravitational effects in the system and be reflected in the measurements. It makes sense there would be a cycle type for Mercury, Mecury + Venus, Mercury + Venus + Earth and so on until the effects become very small.

  4. The Star Man September 19, 2017 / 6:00 am

    Hello, There is no denying that (SOL) is showing a slow down in magnetic energy, we can see this from the last 2 weak cycles 23/24 ( ongoing) we are in a period of transition of the 200 year cycles, if we look at peaks in maximum and lows of minimum it suggests that every 200 years the magnetic energy goes from high to weak. 1700-1900 increase in magnetic energy 1901-2014 decrease in magnetic energy ( and continued decline to date) suggesting cooling of Earth and few sun spots, we also are informed that our magnetosphere is declining!, this also may a trigger and a natural cycle over the same time scales, meaning that the Sun and Earth are harmonious in evolution with the Sun being the main climate driver.
    Your thoughts?.

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