THE SOUTHWORTH PLANETARIUM
70 Falmouth Street      Portland, Maine 04103
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43.6667° N    70.2667° W
Founded January 1970
2022-2023: XXXI
Sunrise: 7:12 a.m.
Sunset: 5:37 p.m.
Civil twilight ends: 6:07 p.m.
Sun's host constellation: Virgo the Maiden
Moon phase: Waxing crescent (12% illuminated)
Moonrise: 11:05 a.m.
Moonset: 7:41 p.m.
Julian date: 2459881.21
"When someone hands you a flyer, it's like they're saying, 'here, you throw
this away.'" Mitch Hedberg (said, presumably, just before a mid-term
election.)

THE DAILY ASTRONOMER
Friday, October 28, 2022
Quiz # 8: There Goes the Sun

[image: sun_large.jpg]

What better time to post a quiz about the Sun!   In a few weeks, the grand
ol' Sol will be utterly absent from our skies except for the occasional
cameo appearances it will make between blinding blizzards.      Now, to be
fair, the Sun's imminent absence is not its fault.  We just happen to be
living on a planet that is zipping merrily along its orbit.  As it moves,
Earth's north pole is alternately pointed toward and then away from its
parent star.  Consequently, we experience seasonal temperature variations.
 90's in the summer to 90 nanoKelvins in the winter.

Now, if we could somehow wrest ourselves away from Earth's enveloping
embrace and soar Sunward, we would observe a furiously hot sphere rendered
blindingly incandescent by the elemental fires of nuclear fusion.   Every
second of every day without fail, relent or hindrance, the Sun "burns"
millions of tons of hydrogen in its superheated core to produce the copious
energy that eventually escapes into outer space.   The planets receive a
meager allotment of this prodigious outflow.  It has been enough to sustain
life on Earth for so very long.

So, what better way to bid adieu -at least for a while- to our brilliant
Sun than with a tribute quiz.


1.  If hollowed out, the Sun could accommodate how many Earth sized spheres?
a.  16,700
b. 113,879
c.  435,978
d.  1.2 million

2.  When is the Sun closest to Earth?
a.  Earth's orbit is circular so its distance from the Sun remains constant
b.  early July
c.  early January
d. the autumnal equinox

3.  About how much of the Sun's energy does Earth receive?
a.  3%
b.  1.5%
c.   one millionth
d.   one billionth

4.  As far as size is concerned, how does the Sun compare to other stars?
a.  it is smaller than most.
b. it is smaller than half of them
c.  it is larger than about 90% of the other stars
d.  the Sun is larger than any other star

5. How old is the Sun?
a.   6006 years old
b.  3.5 million years old
c.  5 billion years old
d.  10 billion years old

6.  True or false:  The Sun is yellow.

7.  True of false:  The Sun will become a black hole in about 6.5 billion
years

8.  The Sun consists primarily of hydrogen and helium.    It contains
"trace" amounts of other elements.   How many other elements have been
detected in the Sun so far?
a.  5
b.  17
c.  34
d.  67

9. How long does the Sun require to complete one orbit around the galaxy?
a.  it hasn't completed an orbit yet and probably never will before it dies.
b. 10 million years
c.  113 million years
d.  225 million years

10.  The energy created in the Sun at this very moment will need how much
time to escape into outer space, approximately?
a.   8.4 minutes
b.  10,000 years
c.  45,000 years
d.  200,000 - 300,000 years

ANSWERS

1.  d.  1.2 million
Now, that's a humbling thought.    Compared to us, Earth is unfathomably
huge!    Compared to Earth, the Sun is immense.   One could pour Earths
into the hollowed out Sun like 200 galloons of Skittles poured into a large
vat.    (Yes, we did the math....no, we probably didn't do it right...)

2.  c.  early January
Yes!    Despite the frigid and bitter conditions of early January when
we're huddled together inside our in home bon-fires while watching globules
of liquid oxygen dripping off the branches, we're actually closest to the
Sun.   Earth reaches perihelion, the point of least distance, around
January 1 - 4.    At this time, we're 91.5 million miles from the Sun.
 When at aphelion around July 4th, Earth's heliocentric distance is about
94.5 million miles.     The distance difference doesn't affect our weather.

3. d.   one billionth
Wow!  I mean, wow!     Venture out into a steamy hot tropical rainforest
and realize that the oppressive heat is almost a negligible fraction of all
the heat energy the Sun generates.

4. c.  it is larger than about 90% of the other stars
Most of the stars are red dwarfs, which are considerably smaller than the
Sun. However, some stars literally dwarf the Sun.  Look at the size
comparisons between the Sun and some of the larger stars

[image: size_comparison.en.png]

5.  c.  5 billion years old
The Sun is about midway through its life cycle.

6. * False!*
Big, bold false!   The Sun appears yellow because of our atmosphere.   In
fact, the Sun would appear white if one approached it in space.    The Sun
produces light along the entire EM spectrum.  It produces the most
radiation along the green portion of the spectrum (483-520 nm).

7. False!
Big, bold, bloated false!  The Sun will never become a black hole.    When
it perishes, the Sun will turn into a white dwarf surrounded by a planetary
nebula.

8. d.  67
We remember that the solar system formed from a nebula chemically enriched
by the introduction of supernova remnants.  Such remnants contain an
abundance of elements.   These particles would have been incorporated into
the Sun.  The three most abundant elements (by number of atoms) in the Sun
are   hydrogen, helium and oxygen.

9. d.  225 million years
A galactic year.    The Sun has completed  more than 20 revolutions around
the galactic center through its life.

10. d.  200,000 - 300,000 years
Every time you are outside on a sunny day you are awash in ancient
starlight.



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