Course Announcements

Course Announcements• Homework: “Scale of the Universe” will be available

on-line at the Mastering Astronomy (MA) website (“masteringastronomy.com”) on Thursday

• ASSIGNMENT #1 IS DUE SEPTEMBER 10th, 11 pm.• These awesome presentations are available on my

home server, http://evilo.dyndns.org/courses You should take a look at these as you begin to study for Test I.

• When is our first test? • September 17...that's a Thursday in two weeks.

Did you get the Key Ideas from the Motion

Lecture Tutorial?

Imagine you are located in the Northern Hemisphere and see a star directly overhead

(zenith). In what direction will you have to look to see this star set?

A) southwestB) westC) northwestD) This star will never set.

You are looking toward the north and see the Big Dipper to the right of Polaris. Fifteen

minutes later, the Big Dipper will appear to have moved in roughly what direction?

A) east (to your right)B) west (to your left)C) up (away from the horizon)D) down (closer to the horizon)

How much time is there between when a star rises and when it sets?

A) less than twelve hoursB) about twelve hoursC) more than twelve hoursD) It depends on the star.

You go out tonight and see the brightest star in the constellation Orion just rising above your

eastern horizon at 10 PM. One week later at 10 PM this same star will be

A) slightly higher in the sky.B) at the same height as before.C) below your horizon.D) setting on your western horizon.

So now we understand nightly motion. How about weekly and monthly changes?

Astrology: The belief that the positions of the stars and planets

as seen from Earth impact human events.

Science or Pseudoscience?

These weekly and monthly changes lead to ...

Your Birth Sign

ROUGHLY, it is the constellation that the Sun is covering up during the day you are born if you were born 2000 years

ago.

Zodiac - The 13 Zodiacal constellations that our Sun covers-up (blocks) in the course of

one year (used to be only 12)

Aquarius Pisces Aries Taurus Gemini Cancer

Leo Libra Virgo Scorpius Ophiuchus Sagittarius Capricornus

Constellations – the 88 semi-rectangular regions that make up the sky

Northern constellations have Latinized Greek-mythology names: Orion, Cygnus, Leo, Ursa Major, Canis Major, Canis

Minor Southern constellations have Latin names:

Telescopium, Sextans, Pyxsis The actual constellation boundaries were

drawn up by Eugène Delporte in 1930 then later approved by the IAU (International Astronomical Union).

Use the Summer Triangle to find constellations during summer evenings

Use the winter triangle to find constellations during winter

evenings

Anyone recognize any shapes here?

Islamic(ish) Star Names

SIRIUS

BetelgeuseAldebaran

Rigel

Using Orion in to find other objects

Sirius

Aldebaran

Pleiades

SevenSisters SubaruPleiades

Using Orion in to find other objects

Sirius

Aldebaran

Pleiades

Great Orion Nebula

Use the Big

Dipper in the

northern sky as a way to

find other groups of

stars

How to find stuff in the sky – Star Charts

http://skymaps.com/

http://www.fourmilab.ch/yoursky/cities.html

http://www.astro.wisc.edu/~dolan/constellations/constellationjavalist.html

Tutorial: Seasonal Stars – p. 7 Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another

group. If you get really stuck or don’t understand what the

Lecture Tutorial is asking, ask me for help.

Post Tutorial Question

What component of Earth’s motion causes 〠 the stars to rise earlier on successive nights?

A) its rotation about its axis B) its orbit around the Sun C) the tilt of its rotation axis

Post Tutorial Question

One night, you see the star Sirius rise at exactly 7:36 PM. The following night it will rise

A) slightly earlier. B) at the same time. C) slightly later.

Post Tutorial Question One evening at midnight, you observe Leo high in

the southern sky at midnight. Virgo is to the east of Leo and Cancer is to the west. One month earlier, which of these constellations was high in the southern sky at midnight?

A) Leo B) Virgo C) Cancer

GO CONFIDENTLY (To the Physics Lab) IN THE DIRECTION OF YOUR DREAMS!! LIVE THE LIFE YOU’VE

IMAGINED