PowerPoint Presentation

How does the altitude of Polaris change?We will be taking a virtual field trip to different spots on the Earth and viewing the stars there. We are going to focus in on two major constellations, and one very important starPolaris, or the North Star.

Altitude: the angle of a celestial object above the horizon

Constellation: group of stars that form a pattern and are used to help people locate celestial objects

Latitude: angular distance north or south of the equatorThrough the magic of virtual astro-vision, we will be viewing the sky at the same time in every location we go to! We need to do this so that we can see the sky the same way at each location. As you may already know, our view of the constellations change over an eveningthe stars appear to move because the Earth is rotating!****Your view of the sky at 9:00 p.m. is different from your view at 11:00 p.m., just for example.****Polaris is the exception to this!!!We are going to deal with this problem by arriving at each location at precisely the same timethrough our superstellar supersonic time machine (SSTM)!

Hop on board!

Our first stop is really close by! Central Park in New York City!

New York, New York 41o N LatitudeBig DipperCassiopeiaPolarisPointer Stars

We are going to calibrate our screen so that we can make measurements of the location of Polaris in other places on Earth.We will be using a device called a sextant. This measures the stars angle above the horizon. This is called ALTITUDE.This simulation is only in 2-D, so the sextant appears like a ruler. However, in the real-world of 3-D, this device would measure what angle you have to tilt your head up in order to see a star. Therefore, if the star is at the horizon, the angle is ZERO. Directly overhead, the angle is 90o.

New York, New York 41o NBig DipperCassiopeiaPolarisPointer Stars Measure the altitude of Polaris

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41oPOLARISHORIZONThere is a 41 degree angle between the horizon and Polaris.In other words, the viewer must tilt his or her head (and telescope!) up 41o from the horizontal in order to directly see Polaris. What does this view feel like in 3-dimensions? The arc represents the Celestial hemisphere (the sky above)The ground

What is the latitude of NY city?Now lets head to Tampa, Florida and view the night sky there!

Tampa, Florida What is the altitude of Polaris in Tampa? (Use the pointer stars of the Big Dipper)

010203040506070What is the altitude of Polaris in Tampa?Again, lets draw it in 3-D on the celestial sphere diagram!

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HORIZONWhat does this view feel like in 3-dimensions? The arc represents the Celestial hemisphere (the sky above)The groundIn Tampa, would you tilt your head up more or less than in New York in order to see Polaris?Plot the position of Polaris for Tampa

Tampa, Florida

010203040506070Did you notice that the Big Dipper, and Cassiopeia are also lower in the sky here

New York, New York 41o N

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What is the latitude of Tampa?Now we are flying off to Popayn, Colombia in order to view the tropical night sky!

Popayn, ColombiaWhat is the altitude of Polaris in Popayn?

010203040506070What is the altitude of Polaris in Popayn ?Again, lets get a feeling of what this looks like in 3-D!

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HORIZONWhat does this view feel like in 3-dimensions? The arc represents the Celestial hemisphere (the sky above)The groundIn Popayn, how would you have to orient your head so you could see Polaris?Plot the position of Polaris for Popayn

What is the latitude of Popayn?Predict where you would find Polaris if you were at the Equator (Oo)Lets see if you are getting the hang of this! For our next stop we are going to view the sky FIRST, and then predict our latitude from our view of Polaris!Pretty neat, huh!

Mystery Location

Before, we measure, determine this: Are we North or South of NY?Here is NY again for comparison

New York, New York 41o N LatitudeAnd now back to our mystery location!

010203040506070O.K.! Lets determine the altitude of Polaris

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HORIZONSo where is Polaris in this location? The arc represents the Celestial hemisphere (the sky above)The groundSo now we know what latitude we are at. What is it?

Of the choices given, where in the world are we?New Orleans, LAWashington, D.C.Hartford, CTQuebec City, CanadaChurchill, CanadaNow that youre so good at this, predict the altitude of Polaris at the North Pole!Lets imagine what it would be like to do this at the North Pole.

Be careful you dont strain your neck!and make sure you are EXTRA good while you are here!!!! You know whos watching.

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90807060 What is the altitude of Polaris?

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HORIZONWhere is Polaris at the North Pole? The arc represents the Celestial hemisphere (the sky above)The groundDescribe what you would have to do in order to view Polaris at the North Pole.All aboard for our last stop! Another mystery location for you to solve!

To give you a hint, well place a marker where Polaris would be if we were in New York at this timeDo the measurement

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Of the choices given, where in the world are we?Meridian, MSHavana, CubaPhiladelphia, PAOttawa, CanadaChurchill, Canada

Well, our adventuring is over for today! Thanks for making our mission a success!

Well, our adventuring is over for today! Thanks for making our mission a success!

Well, our adventuring is over for today! Thanks for making our mission a success!

Well, our adventuring is over for today! Thanks for making our mission a success!

Well, our adventuring is over for today! Thanks for making our mission a success!

Well, our adventuring is over for today! Thanks for making our mission a success!WHEE!See you next time!!!!!Question #2 from the June 2006 Regents