THE USM SOUTHWORTH PLANETARIUM
207-780-4249     www.usm.maine.edu/planet
70 Falmouth Street     Portland, Maine  04103
43.6667° N                   70.2667° W
Altitude:   10 feet below sea level
Founded January 1970
Julian date:  2458639.5
                   "From the world of waking dreams."

THE DAILY ASTRONOMER
Wednesday, June 5, 2019
Quiescent Sun

Greetings!
We invite you to look below:

[image: unnamed-e1542747467803.jpg]

See them?  The Sun spots?
Well, perhaps not, as there are no Sun spots currently visible on the
section of the solar surface.   Today is the 17th consecutive "spotless"
day.    So far this year, we've experienced 91 spotless days.   No sunspots
were visible on 221 days in 2018; 104 in 2017 and only 32 in 2016.
 This apparent increase in spotless days has induced solar scientists to
conclude that we are currently passing through a quiescent phase, known
less pretentiously as a 'solar minimum.'
Every eleven years the Sun moves through a somewhat regular cycle of solar
maximum to solar minimum.  The Sun shows an abundance of spots around
maximum and a dearth around minimum.     See graphic below

[image: wolfaml2.png]

For reasons that solar scientists haven't yet fathomed, the Sun has
proceeded through these alterations of minima and maxima since record
keeping began.  What is also uncertain is the effect this cycle has on our
weather cycle.  It is possible that this impending minimum might reduce the
solar constant (the measure of the solar energy reaching Earth) enough to
cool our weather.

We know that the solar constant at solar maximum is about 1,362 Watts per
square meter.  At solar minimum, this constant measures about 1,361 Watts
per square meter.   This variation is comparable to that we experience due
to Earth's varying distance from the Sun.  The Solar constant varies by
about 3 percent between our closest approach (perihelion, around Jan 3) and
greatest distance (aphelion, around July 4th)  For this reason, many
astronomers remain doubtful about the solar cycle's impact on our weather.

On the other hand, between 1645 - 1715, the Sun experienced a protracted
minimum,  called the "Maunder Minimum."   During those seventy years, the
Sun exhibited a few dozen sunspots in a span of time it should have shown
us about 50,000.     This time period happened to coincide with an
unusually cool time span dubbed  "Europe's Little Ice Age."        Whether
or not this was a correlation or causation is an issue that we have yet to
have resolved.    It might well have been coincidental or, in fact, that
long solar minimum did give the third world an unusual chill.

Will our weather become a bit cooler now?
Well, here along New England's upper rafters, we feel the urge to blame
something for the winter chill that has insinuated itself into the many
hours we called our "warm season."  Is it all related to a quiescent Sun?
   If so, we can finally assign blame, even if we'd find it more
problematic to exact revenge.