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: 2457634.16
"Out in the wild black yonder."
*As this is the first quiz of the new DA School Year, we wanted to announce
a couple quiz changes, as well. First, we'll elaborate more on the
answers. Secondly, we'll re-introduce the "ratings system," which
assigns desigations to players based on the quiz performance. We don't
mind including this feature as well, although we will be quite careful not
to insult anyone. Oh, and, of course, there are the Roman numerals we'll
assign to the quizzes through the school year to make us seem far more
important than we actually are. *
*THE DAILY ASTRONOMER*
*Friday, September 2, 2016*
*Quiz I: All Things Bright and Astronomical*
From lunar phases and meteors to galactic superclusters and the cosmic
microwave background radiation, astronomy is just about anywhere,
everywhere, and in all places in between. This first quiz of the 2016-17
school year focuses squarely and cubely on all things astronomical. As
we've already established, that covers so much territory that even a 1000
question quiz would scarcely scratch the surface. Don't panic. It will
be awhile before we entertain you with a quiz like that.
1. What is a "blue moon?"
a. the name of the full moon when it is at the zenith (point directly
overhead.)
b. the name givent to January's full moon
c. the second full moon in a given calendar month
d. a name often given to Venus as it rises
2. Earth has a magnetic north and magnetic south pole. Which ONE of the
following statements about them is not correct?
a. Geographically, they are not diametically opposed (180 degrees apart).
b. Both poles drift
c. The magnetic north pole is currently aligned precisely with the
geographic north pole
d. The Aurora Borealis ("Northern Lights") and Aurora Australis ("Southern
Lights") are centered around these poles.
3. If you are looking at the "gegenshein", what are you seeing?
a. an image of the false sun appearing in the night sky
b. the aurora borealis
c. the dark patches within the Milky Way
d. an unusually bright comet
4. Which planet appears the brightest in the night sky from our
perspective?
a. Mercury
b. Venus
c. Mars
d. Jupiter
e. Saturn
5. Around which planet will one find the Galilean Moons?
a. Jupiter
b. Saturn
c. Uranus
d. Neptune
6. In September, one would expect to find Orion's Belt in the
__________________ part of the sky around ________________________.
a. eastern; 8:00 p.m.
b. eastern; 4:00 a.m.
c. southern; midnight
d. western; 10:00 p.m.
7. Which ONE of the following cannot be created by a supernovae?
a. black holes
b. white dwarfs
c. neutron stars
d. nebulae
8. What is meant by a star's "luminosity?"
a. the amount of energy it emits every second
b. its temperature
c. its distance from Earth
d. its chemical composition
9. Galactic and globular clusters are quite different. Which of the
following statements about their differences isn't true?
a. Galactic clusters are much smaller than globular clusters
b. Galactic clusters are much younger than globular clusters
c. Galactic clusters have a lot more stars than globular clusters
d. Globular clusters populate the halo surrounding the galactic nucleus,
whereas galactic clusters are generally found within the outer disc of the
galaxy
10. What is the name of the cluster of more than 54 galaxies to which the
Milky Way Galaxy belongs?
a. The Local Group
b. The Virgo Coven
c. The Capricornus Consortium
d. The Sagittarius Assembly
ANSWERS
*1. c. the second full moon in a given calendar month*
The period of time separating two successive full moons -called its
"synodic period"- equals 29.53 days. Every month, save February, is
longer than the lunar synodic period. Therefore, one can have a blue moon
in any month except February. A 'blue moon' is also defined as the
fourth full moon in one season. The second definition is considered
the original, while the first definition arose later.
*2. c. The magnetic north pole is currently aligned precisely with the
geographic north pole*
The north magnetic pole is not aligned with the north geographic pole.
Presently, the north magnetic pole is centered on 86o 24' N 166o 18'
W. The pole drifts by 55 - 60 kilometers per year. The south magnetic
pole is presently positioned at 64O 17' S 136O 35' E Earth's magnetic
field is not symmetrical, so these poles are not 180 degrees apart.
*3. a. an image of the false sun appearing in the night sky*The word
"gegenshein" is a German term meaning "counter shine." It sometimes
appears in the night sky when dust particles along the ecliptic (the Sun's
apparent annual path) reflect light fron the Sun, which will be 180o away
from this gegenshein. The best time to view this effect is around
Oct/Nov and between midnight and 1:00 a.m. Even at these ideal times, the
gegenshein is still not an easy sight to behold. It is a subtle effect,
much like the zodiacal glow, which is also caused when dust reflects
sunlight along the ecliptic.
[image: cid:image004.jpg@01D1F57D.B3B31470]
*Can you see the "gegenshein?" Look for the elliptical light patch
against the starfield.*
(Image by ESO/Stéphane Guisard )
*4. **b. Venus*
The moon is the only night sky object brighter than Venus. There are
four factors determining a planet's brightness. Its distance from the Sun,
its distance from Earth, its size and its albedo, which measures the ratio
of light reflected to light received. Venus is closer to the Sun. Venus
is also one of the closest planets to Earth (Mars is the other). Unlike
Mars, Venus is only slightly smaller than Earth. Also, its albedo is 0.65,
meaning that it reflects 65% of all sunlight back into space. Jupiter
is the second brightest planet. However, even if Jupiter were at its
maximum brightness at the same that that Venus were at its minimum
brightness, Venus would still be more than 2.5 times brighter than Jupiter!
*5. **a. Jupiter*
The Galilean moons are Io, Europa, Ganymede and Callisto. They are so
named because Italian astronomer Galileo Galilei (1564-1642) discovered
these Jovian satellites in 1610.
*6. **b. eastern; 4:00 a.m.*
Orion has returned, but is currently a pre-dawn object in the eastern
sky. Stars rise four minutes earlier each day as a consequence of
Earth's orbital motion. So, as we move through autumn, Orion's belt will
rise progessively earlier and by winter will become a prominent winter sky
asterism.
*7. **b. white dwarfs*
A white dwarf is a stellar remnant produced when any star less massive than
8 solar masses reaches the end of its life cycle. These stars expel their
outer layers to form planetary nebulae. This "planetary nebula," -so named
because of its resemblance to a planet when viewed telesopically- will then
expand away from a white dwarf core. The composition of this core depends
on the initial mass of its progenitor star. A very low mass star will
produce a helium rich white dwarf, while a more massive star (that is will
under 8 solar masses) will create a whigte dwarf rich in heavier elements
such as neon and magnesium. [Note: white dwarfs lose thermal energy
through the painfully slow radiative process. As they cool, white dwarfs
exhibit different colors. Eventually, they'll turn to black dwarfs when
they become sufficiently cool. Some white dwarfs might require about one
trillion years to cool to the black dwarf state, a time period far
exceeding the Universe's estimated age of 13.8 billion years.
Consequently, no black dwarfs have yet been detected.]
*8. a. the amount of energy it emits every second*
A star's luminosity relates to its energy output. A star's luminosity is
determined by its mass. The more massive the star, the more luminous it
will be. Luminosity is also related to a star's size and temperature. If
you double a star's size, its luminosity increases four time. If you
double a star's temperature, its luminosity increases 16 times!
*9. c. Galactic clusters have a lot more stars than globular clusters*
This statement isn't true. A globular cluster contains hundreds of
thousands or even millions of stars, whereas the galactic clusters consist
of hundreds or thousands. Galactic clusters also tend to
disassociate after a few hundred million years. (Our Sun was originally
part of a cluster that has long since dissipated.) With ages often
exceeding 10 billion years, globular clusters are amongst the oldest
structures in the Universe.
*10. a. The Local Group*
The Local Group of Galaxies consists of more than 54 galaxies, most of
which are dwarf galaxies. The Milky Way Galaxy and the Andromeda Galaxy
are the two largest members. The diameter of this region just exceeds 10
million light years.
*[image: cid:image003.jpg@01D1F54B.9A1EFF10]*
*Omega
Centauri
*
*A globular cluster in the constellation Centaurus*
*Globular clusters are larger, older and contain
more *
*stars than galactic clusters
Age:
11.5 billion years
*
*(Image: ESO La Silla Observatory) *
*[image: cid:image004.jpg@01D1F54B.9A1EFF10]*
*Pleiades Star Cluster**A galactic cluster in the constellation Taurus*
*Galactic clusters tend to contain a few hundred stars*
*and are quite young. *
*Age: 120 million years*
*(Image by NASA, ESA, AURA/Caltech, Palomar Observatory)*
*RATINGS:*
*10 CORRECT: SPACE SCIENCE SORCERERYou were conjuring over a cauldron
while all the other kdis were outside playing capture the flag. You're a
wizard on every level from the lunar to the cosmological. You could
even be a Harry Potter character, but, of course if you are, you won't
actually say anything or be involved in the plot. *
*7 - 9 CORRECT: COSMIC CRACKERJACKYes, we know you missed a couple of the
questions on purpose so your friends will still think you're mortal. You
are secretly soaring along the stratosphere and can ascend above the Karman
Line whenever the mood moves you. *
*3 - 6 CORRECT: ASTRONOMICALLY AVERAGENo worries! The Sun is an "average"
star and well developed ancient warriors once thought very highly of it.
*
*0 -2 CORRECT: LOOK ON THE BRIGHT SIDE*
*Your social life is intensely active and we envy you for it.*
*-------------------------------------------------------------------------------------------FROM
THE CATACOMBS OF INFINITE KNOWLEDGE*
*The development of the theatre predated the invention of electric lights.
Before electric lights were available, a theatre would cast its stars in
an intense light generated by burning lime in a lamp. From this practise
we derive the term "limelight." *
*____________________________________________________*