Astronomy 1020-HSpring_2015

Day-1Stellar Astronomy

ASTR_1020_Day-1 Dr. Allyn Smith Office Hours: (B329-SSB): MW 1130-1300 &

by app’t. Lecture-Tutorials & Text Book D2L – Will be used for grade tracking only.

Do NOT send email via D2L – it probably will not be read.

Everything you need for this class can be found at: http://www.apsu.edu/astronomy

ASTR_1020_Day-1 Goals for the class:

Understanding of the scientific process Concepts of the basic physics of astronomy How we obtain information about the stars Star & Galaxy formation Star & Galaxy evolution The Sun The Universe Life and other weird stuff

ASTR_1020_Day-1 Text Book: 21st Century Astronomy, 4th Edition

By Kay, Palen, Smith, & BlumenthalORDER FROM: Amazon.com or visit Study MasterISBN: 978-0-393-91878-6 (Full book) – if you plan

to also take ASTR-1010: Intro. To Planetary Astronomy

ISBN: 978-0-393-92057-4 (Stars & Galaxies)

Also: Lecture-Tutorials for Introductory Astronomy By Prather, Slater, Adams, & Brissenden Bring this book to class EVERY day. It will be

used a lot. It is a workbook to be written in!

ASTR_1020_Day-1 Observing:

1st quarter moon nights – 3 of them this semester

You MUST attend at least one. Will be held cold, rain, snow, or clear. 6 Dark Night observing sessions – you must

attend 1: Weather dependent Notice posted on astronomy URL by 5pm.

Report due by Wed. Apr. 22 by class time. Format is on the web site.

Dates are on the web site.

ASTR_1020_Day-1 Honors Class Extras:

You will engage in a semester long ”research project” to determine the rotation rate of the Sun at various solar latitudes.

AND

You will watch the sunset (or sunrise) through out the semester to determine motion and rates of motion (if any) along the horizon. Details on Friday.

ASTR_1020_Day-1 Exams:

Four, ”1 hour” exams (~30 MC + 1-2 discussion/problem)

The lowest grade will be dropped The last one will be given during the final exam time Final – You MUST take it.

It will not be dropped. 5-6 discussion questions – comprehensive.

BONUS POINTS: Wear Hawai’ian shirts on exam days; Attend a planetarium show (or two); attend a BSAS star party or meeting.

ASTR_1020_Day-1 On-Line Homework System:

This class will use the Norton Publishing ”Smartwork” system for homework. Instructions are on the web site for the class. You will need a valid school e-mail address; the registration code (comes with the textbook); and the enrollment code (on the Smartworks instruction sheet).

You MUST have a permanent account established BY Friday Jan. 30.

ASTR_1020_Day-1 Assingment: Read Chapter 1. Think about the process outlined in the

Scientific Method and how it is used to investigate and explain observations. What is key to the process? Think of an example where the scientific

method could be used.

Modern astronomy is more than cataloging objects.

How do stars (matter and energy) work?

What is the universe?

How do humans fit in?

Earth is a small planet,

orbiting a medium-sized star,

in a galaxy of 100 billion stars,

which is just one of billions of galaxies,

in a universe that is 13.7 billion years old.

The universe is vast. Billions of galaxies

are separated by thousands of trillions of miles.

Astronomers need to be able to talk about great distances.

Use the travel time of light to measure distances.

We often use times to denote distances. For example, we may say a friend’s house is

two hours away. Compare distances by the amount of time it

takes to travel them.

Light travels 300,000 km every second. Universe’s greatest speed. Light-year: distance light travels in one

year. Light could travel around Earth in 1/7

second.

Light Travel Times

Light takes:• 1¼ seconds to arrive from the Moon.• 8.3 minutes to arrive from the Sun.• 5.5 hours to get to Pluto from the Sun.

Light takes:• 4.2 years to arrive

from the nearest star.

• 100,000 years to cross the galaxy.

• 2.5 million years to get to the nearest big galaxy.

• 10 billion years to come from distant galaxies.

Studying the universe can reveal many things.

For example, except for the hydrogen in water (H2O), all the atoms in our body were made in stars.

Stars generate energy by making heavier elements out of light ones.

Dying stars eject those elements into space in massive explosions.

New stars and planets (and humans) form.

We are stardust, made from the materials provided by earlier generations of stars.

Test scientific ideas by observation. Space exploration has expanded our view

of planets and the Solar System. Telescopes, satellites, etc., extend it more.

Science involves the use of theories, hypotheses, and principles.

A scientific hypothesis s an idea that leads to testable or falsifiable predictions.

The cosmological principle is a very important underlying assumption: • “There is nothing special about our place in the

universe.”

Cosmological principle on one level:• Our view from the Earth is not special or unique.• Distant objects should be like nearby ones, which

we can study in detail. On another level:

• Matter and energy obey the same physical laws everywhere.

• We can learn about distant objects by studying nearby ones.