THE SOUTHWORTH PLANETARIUM
207-780-4249      www.usm.maine.edu/planet
70 Falmouth Street     Portland, Maine 04103
43.6667° N                   70.2667° W
Founded January 1970
Julian date:  2457722.16

              " Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning."

                 -Albert Einstein

THE DAILY ASTRONOMER
Tuesday, November 29, 2016

The Sun Lives

Consider today's headline to be a gentle reminder that the Sun not only lives, but continues to produce prodigious amounts of energy deep in its roiling Dantean core.   In fact, during the brief period of time you spent reading the first sentence, the Sun converted more than 3 billion tons of hydrogen into helium and, in the process, transmuted some of the initial matter into energy.    This newly minted energy has just now started the arduous 100,000 year migration from the core to the photosphere, where it will escape into unbounded space.  

The Sun lives

despite the recent dire pronouncements promulgated by the press that the "Sun is dead."    This statement refers to the Sun's unexpected "quiescent period" as observed by NASA's Solar Dynamics Observatory.    The Sun is known to progress through a 22-year solar cycle during which the sunspot activity ebbs and flows with an almost pendulum-like regularity.        The Sun is currently in solar cycle 24, which began in 2008.  Were the Sun to abide dutifully to its sunspot cycle, it would be at its next minimum around 2021.     However, the Sun has lapsed into a stupor and this year has experienced 25 'spotless days," more than any year since 2010.

The Sun's deviation from its expected behavior has occasioned anxiety in many solar astronomers.     This variance attests to our limited understanding of the mechanisms responsible for the formation and duration of sunspots.   Sunspots are believed to be caused by gases extracted and cooled by magnetic fields.  These cooler regions would appear red if viewed in isolation, but in contrast to the much brighter areas around them, look quite dark.      Increased solar activity produces more of these spots, so astronomers can measure the activity cycle by spot counting.     

Even though the 22-year solar cycle seems well established, it is based only on about four centuries of observations: 0.000008% of the Sun's age.    Deviations from this cycle are to be expected as solar scientists strive to demystify the process that governs it.   As more data becomes available, the solar cycle might be redefined and its duration re-calculated.      As for now, solar physicists cannot know if the Sun is starting a new prolonged minimum, or if this is just a brief interruption in the regular solar cycle.

​

The Solar Record.    A record of the Sun's sunspot number since the 17th century.   We observe the deep Maunder Minimum (1645-1715) and then various peaks as valleys through the subsequent centuries, sometimes interrupted by other minima, most notably the Dalton Minimum (1790-1830).      Image:   SOHO.com 

The notion of a protracted minimum frightens some climate scientists who worry that such a minimum would induce a cooling period on our planet.   This concern stems from the correlation between the Maunder Minimum and "Europe's Little Ice Age," which occurs around the same period.        Whether or not this correlation is actually a causation or just coincidental remains a contested issue.         

It is because of all this uncertainty that we're now seeing that dire headline "The Sun is Dead."   And, you know, we could do without such headlines!     

Now, astronomers have assured us all that the Sun's autumnal descent toward its solstical nadir results from the same planetary tilt and revolutionary motion that will ultimately re-elevate it back to its lofty position.    Nevertheless, the assailing hiemal helm winds of our tempestuous winter awakens in us hinterland dwellers  a deep-seeded disquiet stemming from the primal days when our remote ancestors cast a wary eye on that empyreal orb.     The fiery sphere which bestowed its life-sustaining warmth on the world was mysterious and thus its beneficent fires were thought to be exhaustible.*    The Sun that shone high and bright in the summer might well have descended into eternal oblivion in the winter, cosigning the helpless mortals to everlasting cold and darkness.   Although modern science has admittedly allayed these concerns,  we retain vestiges of this ancient terror when ice arrests the flowing waters and snow shrouds absorb nature's subtle harmonies.     And, on those days, we remind ourselves that, though either unseen or lingering low behind cloud banks,   the Sun lives....

and nothing could make us happier.

*As it turns out, the Sun is exhaustible, but will still persist for billions of years.  

© 2016  Edward Gleason