Celestail Guide for mariners

Milky Way Galaxy Gallery Adler Planetarium & Astronomy Museum • • • Gallery Guide: Milky Way Galaxy Pre-Visit Activity: Life Cycle of Stars Post-Visit Activity: Make a Star Finder Portions of this material are based upon work supported by the National Science Foundation under Grant No NSF-9725676 Adler Planetarium & Astronomy Museum Education Department 2001 Milky Way Galaxy Gallery Begin your journey in the 3-D Milky Way Theater, as you explore our galaxy, the Milky Way Find the “Size Wise” exhibit and test the different scales What things can you think of that are the same size, but different mass? How does the mass of a marshmallow compare to the mass of a flashlight battery? Go to the bench seat with a circular metal centerpiece by the windows There are constellations etched in the metal Find Ursa Major in the constellations Part of that is what we call the Big Dipper Make a rubbing here of Ursa Major: Explore “The Real Life of Stars” exhibit to learn about the life cycle of stars Where are stars born? What stage is our Sun in its life cycle? What is a supernova? Will our Sun ever become a supernova? Why or why not? Adler Planetarium & Astronomy Museum Education Department 2001 Use the “Supernova” computer stations to match the star size to its fate Stellar Mass Small (less mass than the Sun) Outcome brown dwarf Sun-like (low mass) planetary nebula Massive stars (10x more massive than our Sun) pulsar Most massive (30x more massive than our Sun) black hole Find the large display called “Lagoon Nebula” located in the back of the gallery, by the windows Describe the picture What can we learn from this picture and the nebula pictured in it? Go inside the large dome In the first column of this chart, list the kinds of energy given off by the sun In the second column, list any ways the light is used by astronomers, or any other ways that you have heard of these kinds of light Kinds of light I’ve heard of this before! _ _ (shortest wavelength) _ _ _ _ _ _ _ _ (longest wavelength) Adler Planetarium & Astronomy Museum Education Department 2001 Go to the SOHO video of the sun under the dome towards the end of the gallery, by the exit doors Describe what you see Does the Sun rotate? How you know? Adler Planetarium & Astronomy Museum Education Department 2001 Pre-Visit Activity: Life Cycle of Stars PURPOSE: This activity enables students to enact the lifecycles of different types of stars, thereby illustrating the rarity of black hole-producing stars OBJECTIVE: Students will understand how and when black holes form INTENDED AUDIENCE: 4th-8th grade TIME REQUIRED: 30-40 Minutes MATERIALS: 12 Red, 12 Yellow, 4White, and Blue Balloons (1 balloon/student for a class of 30) Wooden beads Marbles Ball bearings Pin (to pop balloons) Red, yellow, and black markers for writing on balloons Recycle bin for popped balloons Life Cycle of Stars Information Chart (at the end of the lesson) PREPARATION: Place wooden bead inside each red and yellow balloon Place marble inside each white balloon Place ball bearing inside each blue balloon PROCEDURE: Begin by introducing the ways in which stars come into being and produce energy: through gravity’s force and nuclear fusion Nuclear fusion is the bringing together of atoms to form heavier atoms with a release of energy This can best be done, perhaps, by asking students to state their ideas of what makes the stars shine Ask if all stars are the same, and ask students to help make a list of things that might vary between stars: mass, color, heat Make sure to include “life cycle.” Ask if students know how black holes form (answer: they form when certain kinds of stars die) Ask how often students think that black holes form, and if they believe our Sun will form a black hole Don’t forget to ask them to explain the reasons behind their ideas! This information will be helpful to you in determining how best to structure your questions through Adler Planetarium & Astronomy Museum Education Department 2001 the rest of the lesson 4 10 11 information will be helpful to you in determining how best to structure your questions through the rest of the lesson State that the class will an activity that illustrates how all of these differences in stars’ characteristics are related, and will show when, and how often, black holes form Pass out balloons, distributing different colors, one balloon per student You should have significantly more red and yellow balloons than blue and white, roughly 80% red and yellow, 15% white, and 5% blue Explain that the property that causes the main differences between stars is mass As you pass out balloons, tell students the approximate mass of their star Ask students which balloons they think represent the hottest stars Point out that actually red stars are the coolest, and blue stars are the hottest Ask what color our Sun is (yellow) Ask which color star students believe will live longest, and why Write prediction on board Record differing opinions, too Guide students through the following series of steps For each age, tell students what to for their color of balloon To help students follow the progression, you might write different stages on a board or overhead as you move on, and note important events Also, ask students to make predictions as you work After all stars are “dead,” review the sequence you have just covered Point out which stars died first, which last Point out the fate of the yellow stars like our Sun Note that they live quite a long time and don’t become either black holes or neutron stars Point out that black holes are the rarest type of stars in our group EVALUATION: Discuss as a class what they saw at different stages of each type of stars’ life Which stars became black holes? Why did only those stars become black holes? Which stars deflated and which exploded? What is the main difference between those stars? CLOSURE: Compare activity to predictions made at beginning of class Record conclusions drawn from activity next to predictions, pointing out that changing your ideas is part of being a good scientist RESOURCES: For more activities related to this topic, download the Astronomy Connections: Gravity and Black Holes curriculum guide from the Adler Planetarium & Astronomy Museum website at http://www.adlerplanetarium.org/education/ac/gravity Adler Planetarium & Astronomy Museum Education Department 2001 Life Cycle of Stars Information Chart Red Balloons 0.4 Solar Mass (2/5 the mass of our Sun): Red stars Blow up the star to about 3” diameter Wait Do not change diameter of balloon Wait Yellow Balloons Solar Mass (the mass of our Sun): Yellow Stars 500 Million Years Billion Years Age of Star (start) Million Years 10 Million Years White Balloons Solar Masses (3 times the mass of our Sun): White Stars Blow up the star to about 3” diameter Wait Do not change diameter of balloon Blue Balloons Solar Masses (9 times the mass of our Sun): Blue Stars Blow up the star to about 3” diameter Wait Blow up a little more Wait Wait (note that planets are forming) Wait Blow up a little bit Continue to slowly inflate star As it gets bigger, star cools, so color it yellow and red (make squiggles on surface with markers) Quickly blow up star until fully inflated; pop balloon Make sure to catch marble Blow up star as fast and as much as you can When star is fully inflated, teacher pops balloon—a supernova This popped star has become a black hole; all of the super nova remnants can be thrown out into space Blow up the star to about 3” diameter Wait Do not change diameter of balloon Adler Planetarium & Astronomy Museum Blow slightly more air into balloon Still black hole! Education Department 2001 Billion Years Red Balloons Wait Yellow Balloons Blow up more The star is getting cooler, so color it red with marker It is now a supergiant 10 Billion Wait 50 billion years Blow up a little more 200 Billion years Deflate; star has shrunk and died Color black Wooden bead inside is a white dwarf Blow up a little more Outer envelope dissolves, so cut up balloon The inside bead becomes a white dwarf, and the bits of balloon represent the planetary nebula Move “planetary nebula” farther away Place remnants in a recycle bin Nebula is gone Discuss that the white wooden bead turns black to show that it has burned out Blue Balloons This star has exploded Holding on to neutron star (marble), throw supernova remnants into space Place remnants in a recycle bin to demonstrate stellar gas is recycled into new star matter Neutron star White Balloons Still black hole Neutron star Black hole Neutron star Still black hole! Adler Planetarium & Astronomy Museum Black hole Education Department 2001 Post-Visit Activity: Make A Star Finder PURPOSE: This activity teaches students how to use a star finder to locate stars and constellations in the sky OBJECTIVE: Students will be able to: • demonstrate how to use a star finder • explain why the star finder can be used for latitudes between approximately 35 and 45 degrees North latitude • point out where the horizon line is on the star finder • point out where the zenith is • point out where Polaris is • correctly position and hold star finder to be used facing north, south, east, and/or west; and set a date and time on the star finder INTENDED AUDIENCE: 3rd – 12th grade TIME REQUIRED: 15 – 30 minutes MATERIALS: (optional) pre-assembled commercial star finders as a reference star finder blackline template (copied onto cardstock, if available) scissors brass paper fasteners (one per star finder) (optional) crayons PREPARATION: (Optional) If you want to decorate the star finder, so before putting it together Do not color the wheel a dark color, as it will be difficult to read outside in the darkness PROCEDURE: Cut out the star wheel and the wheel housing Find the pointed Sun shape on the wheel housing Poke the brass fastener through the symbol, turn it a bit to create a hole, and remove the fastener Find Polaris on the star wheel (in the middle) Poke the brass fastener points through the dot which indicates Polaris, turn it a bit to create a hole, and leave it in the hole Adler Planetarium & Astronomy Museum Education Department 2001 Put the wheel housing down on the table so the words are face down on the table (the side facing up is all white with no words) Poke the fastener points through the hole in the wheel housing and fold down the fastener leaves to secure Fold the wheel housing where indicated over the star wheel Have students open the star finder to look at the disk of stars Explain that this star wheel is reliable only within certain latitudes (approximately 35 and 45 degrees North latitude) Why is this true? At the North Pole, the North Star, Polaris, will be directly over your head As you travel away from the North Pole, Polaris will be lower and lower in the sky until, at the Earth’s equator, the North Star will be directly on the horizon and not visible at any time As you travel away from the North Pole, constellations around the North Star will be lower and lower in the sky; constellations in the south will be higher and higher in the sky Therefore, a fixed star wheel will only be good for latitudes near the latitude for which it was originally drawn, in this case approximately 40 degrees North latitude Traveling too far from the star finder’s fixed latitude will bring more stars into view in some areas that will be not be shown on the finder and will hide others that the star finder shows should be visible Compare a star finder to a road map: a road map is for finding your way around the Earth; a star finder is for finding your way around the sky A star finder has a “clock”, a “calendar”, and a “compass” to help find stars and constellations at any time of the year Unlike a road map, a star map rotates The Earth spins on its axis, making the sky seem to spin, so the star map needs to spin, too The “compass” is the set of directions on the wheel housing to help orient the star finder in the correct direction (N, S, E, W) Point out the half-oval-shaped feature in the wheel housing Have students slide a finger around the half-oval shape to make sure everyone has found it Have them close the star finder, and slide a finger around the hole again Ask for explanations/guesses of what this shows Explain that the edge of the half-oval window is the “horizon” Ask for a definition of “horizon” The horizon is the imaginary distant line where the ground and the sky seem to meet (The southern edge of the star wheel suffices as the southern horizon.) Ask where “straight up” (zenith) would be on the star wheel (most will guess the brass fastener) Explain that the fastener is important, but not straight up Have students run a finger up from the horizon halfway across the portion of the star wheel that is “visible”, i.e the stars that are above the horizon Halfway into the visible sky is the zenith The brass fastener is slightly off-center Ask what the brass fastener indicates (Polaris/North Star) Each star finder has a “clock” Ask students to find “10 pm” on the star finder Indicate that the times on the star finder are the times when the stars are usually visible (when it is dark) Have them turn the disk until today’s date, the ‘calendar” is set at 10 pm Now the star finder wheel is positioned correctly for a specified date and time 10 To use the star finder, it must be held correctly Face toward one of the cardinal directions (north, south, east, west) Place your thumb on the star finder on the direction (right on the word itself) that you are facing Hold the star finder over your head or directly in front of you so that the direction you are facing is pointing toward the ground For example, face north Place your thumb on the word “north” on the star finder Hold the star finder so that the word “north” is pointing down toward the ground The stars close to the word “north” on the finder will be directly in front of you in the real sky Stars near the word “east” will be to your right, and stars near the word “west” will be to your left Stars in the south will be opposite north and behind you in the real sky Adler Planetarium & Astronomy Museum Education Department 2001 your right, and stars near the word “west” will be to your left Stars in the south will be opposite north and behind you in the real sky 11 To rotate the star wheel correctly, always rotate it counterclockwise so that the stars “rise” in the east and “set in the west” Have students find the Big and Little Dippers (Ursa Major, Ursa Minor) Rotate the star finder wheel to find their positions on any date at any time of night Do they ever set below the horizon around mid-northern latitudes? (Answer: No They never set.) 12 Ask participants to find Orion the Hunter on the star wheel Does Orion ever set below the horizon? (Answer: Yes Orion is not visible during certain months of the year.) EVALUATION: Have students explain the various parts of the star wheel and its correct operation Have students set their star wheels to their birthdays at 10 pm, and identify which constellations are visible in a given area of the sky CLOSURE: Encourage the students to use their star finders at various times throughout the year in order to observe how the constellations visible are changing position Adler Planetarium & Astronomy Museum Education Department 2001 Make A Star Finder: Illustrations horizon Illustration #1: Horizon line Southern edge is assumed to be southern horizon brass fastener zenith Illustration #2: Zenith point Adler Planetarium & Astronomy Museum Education Department 2001 S N E W stars in north E NORTH student facing North thumb North pointing down W stars in south SOUTH student facing South thumb South pointing down Illustrations 3a & 3b - How to hold a star finder correctly E W N S S stars in east stars in west WEST EAST student facing East thumb East pointing down N student facing West thumb West pointing down Illustrations 3c & 3d - How to hold a star finder correctly Adler Planetarium & Astronomy Museum Education Department 2001 Make A Star Finder: Template Adler Planetarium & Astronomy Museum Education Department 2001 Adler Planetarium & Astronomy Museum Education Department 2001