survey of astronomy

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Introduction

Welcome

This is Phys 1040 and Astro 1040

Please pick up one each of the papers on the table up front.

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Introduction

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Introduction

My e-mail

By far the best way to contact me is by e-mail.

twlee2016@gmail.com

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IntroductionMy Web Page

http://www.astro1010-lee.com/

SyllabusCopies of my SlidesLecture NotesLinks

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Introduction

Text There is no Text, only the Slides and Lecture Notes

Tests5 unit testsNO comprehensive finalMust be taken on the day scheduled (I can change the date but you can NOT)Absolutely no late testsMay be taken earlyI DROP YOUR LOWEST TEST SCORE

ASTROLAB(SEE LINK)

• You need to attend one• Dr. Powell offers only a finite number• I recommend that you go to an early one

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Introduction

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Introduction

Select from the list of Subjects that t provide. These are designed to be associated with the lectures. If you email them to me on the designated day you will get full credit, anytime after that is half credit.

Term Papers

EXERCISE 1

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Exercise 1

The purpose of this exercise is for the student to determine the circumference of the Earth using a variation of the Erotosthenes method

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Exercise 1Requires

ProtractorThreadTapeWeight

Find the North Star

Measure the angle from the Horizon to the North Star

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Exercise 1This is how your protractor should look

after you get it ready

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Exercise 1

θ1

NCP NCP

θ2

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Chapter 1Su

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BEGINNINGS

Astronomy -- Study of the UniverseUniverse -- everything that exists

GalaxyThe Milky Way is our GalaxyStarsOpen Star ClustersGlobular Star ClustersNebulaeSunSolar System

Solar SystemPlanetsMoonsAsteroidsCometsOther debrisEarth/Moon System

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Subtend

When an object just fills an angle it subtends that angle.

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Degree (of arc) = 1/360 Circle

Minute (of arc) = 1/60 of a Degree

Second (of arc) = 1/60 of a Minute

Hour (of arc) = 360/24 = 15 degrees

Angular Units

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Distance Measure in Space

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OUR CODE

The Earth and the entire Universe obey a single set of Laws

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Scientific Theory and the Scientific Method

Scientific theories:

must be testable

must be continually tested

should be simple

should be elegant

Scientific theories can be proven wrong, but they can never be proven right with 100% certainty

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Scientific Theory and the Scientific Method

• Observation leads to theory explaining it

• Theory leads to predictions consistent with previous observations

• Predictions of new phenomena are observed. If the observations agree with the prediction, more predictions can be made. If not, a new theory can be made.

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Early Discoveries

Pre-historicSunMoonStarsConstellationsPlanetsMovement of the SkyPath of the SunMovement of the Moon

HistoricCyclic nature of the Universe ….. led to calendars Explanation of the phases of the MoonNCPCelestial EquatorExplanation of the seasons

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Earth’s Orbital Motion

Daily cycle, noon to noon, is diurnal motion – solar day

Stars aren’t in quite the same place 24 hours later, though, due to Earth’s revolution around Sun; when they are, one sidereal day has passed

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From season to season the stars that we see change. This is because of the motion of the Earth in it orbit. The ancients thought it was because the Sun moved around the Earth

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The 12 constellations that the Sun appears to move through during the year are called the zodiac; the apparent path is the ecliptic

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The Earth revolves around the Sun once each year causing the Sun to appear to move around the sky

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• Time from one vernal equinox to next is tropical year

• Combination of day length and sunlight angle gives seasons

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Precession: rotation of Earth’s axis itself; makes one complete circle in about 26,000 years

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The Terrestrial Coordinate System

Latitude is measured north and south from the equator

Longitude is measured east and west from the prime meridian

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Zenith is the point directly overhead

Meridian is the line from the north point through the zenith and on to the south point.

Horizon is the line on the sky made by the plane that is perpendicular to the vertical line from you to the zenith

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The Celestial Coordinate System

Referencepoints andplanes onCelestialSphere

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The Celestial Coordinate System

Right Ascension (RA) or Hour Angle is measured from the point on the sky where the Sun is at the Spring Equinox

Declination (δ) is measured north or south from the Celestial Equator

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Go to Chapter 2

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