What's with the balloons??? - The balloons are used to simulate
both the initial mass function and the evolution of a star cluster.
In a large class, students select a balloon from a bowl
when they enter class. The bowl includes large blue and white
balloons, medium yellow balloons, and small orange and red balloons,
in numbers consistent with a cluster initial mass function.
At the appropriate time in class, students blow up the balloons - the
white, blue, orange, and red balloons are tied off, but the yellow
balloons are not. Once the star cluster is "formed," it is allowed
to age. The blue, and then white, balloons are popped, the yellow
ones are allowed to "fizzle," and the orange and red ones hang
around "forever." I'll usually show Rob Scharein's
HR
Diagram Simulator while the cluster evolves, to guide students
as to when to pop or fizzle their balloons.
(Be sure to have students pick up and dispose of the balloon debris
at the end of class!)
Balloons are also a great way to simulate radiative and convective heat transfer when we learn about the interior of the Sun.
- Essential Facts and Concepts (Word file)
identifies specific facts, definitions, quantities, and relationships that will be used throughout the course and that students must memorize to provide a shared vocabulary.
- Scientific Notation (Word file)
describes the use of scientific notation and provides practice for students.
- Viewing the Sky (Word file)
provides basic instruction in the use of a sky chart and some simple activities while viewing the sky.
- Visualizing the Earth and Moon in Space (Word file)
allows students to practice visualizing the spatial relationships between the Earth, Moon and Sun.
- Electromagnetic Radiation (Word file)
acquaints students with the concepts of frequency and wavelength and provides basic vocabulary for discussing light.
-
The Nearest and Brightest Stars (Word file)
is an exercise in constructing and interpreting Hertzsprung-Russell diagrams.
Students are given data on two stellar populations; the stars which are nearest to our own sun, and the stars which appear brightest when viewed from earth. The data in the tables includes information about each star's distance, absolute and apparent magnitude, and temperature. Each group is asked to make plots of absolute magnitude as a function of temperature for each of these stellar populations. They are then required to identify the main sequence, as well as giant and white dwarf stars, on the resulting HR diagrams. The exercise concludes with a series of questions which analyze the HR diagram, compare brightness with distance, and determine differences between the two samples.
-
Concept Map for Star Formation (PPT file)
helps to organize the process of star formation into concrete steps. Students use a list of terms to fill in a concept map of star formation.
- Ages of Star Clusters (Word file)
includes HR diagrams for six star clusters. Students estimate the distance to and age of each cluster. (The HR diagrams of the clusters are available
here as a PPT file.)
- Nova Aquila 1999 Light Curve (Word file)
asks students to plot a light curve for Nova Aquila 1999.
- Black Holes! (Word file)
encourages students to think about what a black hole is and why they
are difficult to detect. Students are given a graph of Schwarzchild Radius
as a function of mass. A series of questions help students develop a sense
of mass and scale.
- Classifying Galaxies (Word file)
provides images of galaxies for students to classify according to Hubble type.
- The Extragalactic Distance Scale and the Hubble Law (Word file)
introduces students to the proportionality which exists between a
galaxy's distance and recessional velocity. The students are given a
data table containing the velocities and distances in megaparsecs
to several clusters of galaxies, and asked to plot distance as a function
of velocity. Once this has been accomplished and the linear relationship
discovered, there are several questions involving the use of the graph
to estimate the Hubble constant, recessional velocities, etc.
The exercise concludes with an estimation of the age of the universe.
- The Evolution of Galaxies (PPT file)
asks students to compare the types of galaxies found in two galaxy clusters, one
relatively nearby, and one at much greater distance.
- Planets around Other Stars (Word file)
leads student to consider how planets are detected through radial velocity
measurements and how the planets compare to those in our own solar system.
- How Common is Life in the Milky Way? (Word file)
allows students to estimate how common life might be in our galaxy using the Drake equation.
This webpage was developed with the help of Jeff Burkett while he was a graduate student in Astronomy at Indiana University.
