Astro 1 – Sections 2 and 4
The Astronomical Universe
Professor: Robin Ciardullo
Office:
519 Davey Lab
Office Hours:TTh 4:00 - 5:30
Phone:
865-6601
e-mail: rbc@astro.psu.edu
Text: Astronomy - A
Beginner’s Guide, by
Chaisson & McMillan
Class Web Site: http://www.astro.psu.edu/users/rbc/astro1.html
Grades Policy: 50% midterms
25% final
25% homework and clickers
Keys to Success
• Attend class, and ask questions!
• Skim the material before the lectures, and review the
notes afterward. All the notes and the class slides will
be posted on the web a day or two before the lecture.
• Visit the web site regularly. Annoucements, hints, and
extra bonus features will be posted there (without
necessarily being mentioned in class).
• Don’t concentrate on facts. Instead, consider the class
as an exercise in learning the process of scientific
thinking.
• Learn from the tests and the homework. The questions
you miss may appear later on!
Homework
• (Almost) weekly set of
five difficult questions,
posted on-line. The
answers will (usually) be
due by midnight Monday
• Work together!!! Ponder,
discuss, and argue!
• You may submit the
homework multiple times.
Only the last submission
will count.
• Submit the homework on
time! No submission
means negative points!
You don’t have to get all the answers
correct. If you’re getting ~ 70% right,
you’re doing “A” work!
Observing Project
•
•
•
•
Observe the sunset (beginning and end of semester)
Observe the Moon (one time)
Observe planets, stars and constellations (one time)
Observe through a telescope
 Telescopes are open on the roof of Davey Lab (M-Th)
 Telescopes are open to everyone until September 25
 After Sept 25, you can only observe during certain dates
(determined by the first initial of your last name)
Assistance for observing is available on the roof of Davey Lab
Monday through Thursday (starting next week). In addition, the
Astronomy Dep’t and the Penn State Astronomy Club sponsor a
telescope open house every (clear) Friday.
Detailed information is available on the class web-site
TA Help
• Teaching Assistants will be available Monday through
Thursday in 445 Davey Lab to help with questions,
homework, or test preparation. Their hours are
 Monday 1:00 - 6:00 p.m.
 Tuesday 1:00 - 6:00 p.m.
 Wednesday 1:00 - 3:30 p.m.
 Thursday 1:00 - 6:00 p.m.
 Friday 1:00 - 3:30 p.m.
The “Clickers”
You need a Personal Response System (PRS) radio clicker
for this class. (That way, I can keep track of attendance.)
To use (first time):
• Turn the PRS unit on
• When you see “Scanning
classes”, push *
• Push the up arrow key
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
• Enter your PSU e-mail ID by hitting a letter key, then using the
up at down arrows to scroll to the first letter of your e-mail
address. Repeat for the remaining letters (and numbers). After
the e-mail ID is entered, press the green (enter) button.
Next time you turn on the clicker, it will remember your ID!!!
[Note: you should turn your clicker off when not in use so the
battery doesn’t run down.]
The Astronomy Diagnostic Test (ADT)
Outside bureaucrats want everyone to fill out
a brief (40 minute!) online questionnaire
through Angel. This survey won’t be graded,
but participation will count towards your
homework grade. Since the purpose of this
ADT is to find out how much astronomy you
know before taking the course, you should
not study for this. Just answer the questions
the best you can.
The link will disappear on Monday.
STRUCTURE OF COURSE
Visual and Historical
Astronomy
HISTORY OF ASTRONOMY
STRUCTURE OF COURSE
Visual and Historical
Gravity
Astronomy
GRAVITY
QuickTime™ and a
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are needed to see this picture.
STRUCTURE OF COURSE
Gravity
Light
LIGHT
STRUCTURE OF COURSE
Stars
Gravity
Light
STARS
STRUCTURE OF COURSE
The Milky Way
Stars
Gravity
Light
THE MILKY WAY
STRUCTURE OF COURSE
TheGalaxies
Milky Way
Stars
Gravity
Light
GALAXIES
STRUCTURE OF COURSE
The Universe
Galaxies
Stars
Gravity
Light
THE UNIVERSE
STRUCTURE OF COURSE
The Solar System
The Universe
Galaxies
Stars
Gravity
Light
THE SOLAR SYSTEM
STRUCTURE OF COURSE
Life, the Universe
and Us
The Solar System
The Universe
Galaxies
Stars
Gravity
Light
LIFE IN THE UNIVERSE
The Sky and the
Motions of the Earth
The Celestial Sphere
• Geocentrially speaking, the
Earth sits inside a celestial
sphere. Fixed on the
sphere are stars.
Constellations
• Constellations are patterns of
stars that the eye picks out.
The stars are usually not near
each other; they just lie in the
same direction.
• Historically, the brightest stars
are stars of the 1st magnitude.
The next brightest are stars of
the 2nd magnitude. The
faintest stars one can see by
eye are 6th magnitude. (The
biggest telescopes can reach
m = 26 or so.)
Orion, the Hunter
Scorpius, the Scorpion
Leo, the Lion
Cygnus, the Swan
Antlia, the Air Pump
Puppis, the Poop Deck
Constellations
Andromeda (Princess)
Circinus (Compasses)
Lacerta (Lizard)
Piscis Austrinus (Southern Fish)
Antlia (Air Pump)
Columba (Dove)
Leo (Lion)
Puppis (Poop Deck)
Apus (Bird of Paradise)
Coma Berenices (Bernice’s Hair)
Leo Minor (Little Lion)
Pyxis (Compass Box)
Aquarius (Water Bearer)
Corona Australis (Southern Crown)
Lepus (Hare)
Reticulum (Net)
Aquila (Eagle)
Corona Borealis (Northern Crown)
Libra (Scales)
Sagitta (Arrow)
Ara (Altar)
Corvus (Crow)
Lupus (Wolf)
Sagittarius (Archer)
Aries (Ram)
Crater (Cup)
Lynx (Lynx)
Scorpius (Scorpion)
Auriga (Charioteer)
Crux (Southern Cross)
Lyra (Lyre)
Sculptor (Sculptor)
Boötes (Herdsman)
Cygnus (Swan)
Mensa (Table)
Scutum (Shield)
Caelum (Engraving Tool)
Delphinus (Dolpin)
Microscopium (Microscope)
Serpens (Serpent)
Camelopardalis (Giraffe)
Dorado (Swordfish)
Monoceros (Unicorn)
Sextans (Sextant)
Cancer (Crab)
Draco (Dragon)
Musca (Fly)
Taurus (Bull)
Canis Venatici (Hunting Dogs)
Equuleus (Little Horse)
Norma (Carpenter’s Square)
Telescopium (Telescope)
Canis Major (Big Dog)
Eridanus (River)
Octans (Octant)
Triangulum (Triangle)
Canis Minor (Little Dog)
Fornax (Furnace)
Ophiuchus (Serpent Bearer)
Triangulum Australe (Southern
Triangle)
Capricornus (Sea Goat)
Gemini (Twins)
Orion (Hunter)
Tucana (Toucan)
Carina (Keel)
Grus (Crane)
Pavo (Peacock)
Ursa Major (Big Bear)
Cassiopeia (Queen)
Hercules (Hercules)
Pegasus (Winged Horse)
Ursa Minor (Little Bear)
Centarus (Centaur)
Horologium (Clock)
Perseus (Hero)
Vela (Sails)
Cepheus (King)
Hydra (Water Serpent)
Phoenix (Phoenix)
Virgo (Maiden)
Cetus (Whale)
Hydrus (Water Snake)
Pictor (Painter’s Easel)
Volans (Flying Fish)
Chamaeleon (Chameleon)
Indus (Indian)
Pisces (Fishes)
Vulpecula (Fox)
Diurnal Motion
• The Earth’s axis of rotation
also defines some places on
the celestial sphere.
• The celestial North pole is
over the Earth’s north pole.
• The celestial equator is the
extension of the Earth’s
equator.
• The meridian divides east
from west on the sky.
Diurnal Motion
• Each day, the Earth rotates
once (west-to-east) on its
axis. This causes us to face
different directions and see
different stars. The stars’
daily (diurnal) motion
reflects the Earth’s spin.
Risings and Settings
The spin of the Earth causes the stars to appear to rotate
about the celestial pole. Some stars are circumpolar and
never set, while others dip below the horizon. Which stars
are which depends on where you are on Earth.
The 2nd magnitude star Polaris happens to be very near the
North celestial pole.
The Yearly Motion
In addition to rotating, the Earth also revolves about the Sun.
As the Earth revolves
the Sun is projected in
front of different
constellations at
different times of year.
The path the Sun takes
across heavens is called
the ecliptic. The
constellations which the
Sun passes through are
zodiac constellations.
Because the Sun is bright, we can only see some
constellations at certain times of year.
The Seasons
Since the plane of the ecliptic is tilted 23.5° with respect
to the celestial equator, we have seasons.
The Motion of the Sun
From the Geocentric point of view, the Sun moves from the
northern part to the southern part of the sky with the seasons.
When the Sun is furthest north (south), it’s the summer (winter)
solstice. When the Sun crosses the celestial equator, it’s the
vernal (or autumnal) equinox.
Next Time -- Sun, Earth and Moon