Teacher Notes - How Old Are the Jewels?
- In addition to copies of materials in this website, students will
need markers and rulers with centimeters marked. If you have a class
set of hand lenses, they may be helpful to see and classify the
smaller stars on the print, depending on the quality of the print.
- Students should be aware of: a) stellar distances, b) stellar color
and how it relates to temperature, and c) the relationship between stellar
brightness and distance, before they do this activity.
- Prints can be reused if they are laminated (note: avoid wax printers
whose output can not be laminated). After the Jewelbox image is laminated,
use scissors to separate the StarGauge from the image itself.
- The size of the data square can be varied according to the attention
span of your students. Some teachers have suggested that smaller squares
may suffice for younger students, although the limited sample size may result
in a more difficult determination of age. To get a better feeling of looking
through a telescope at the cluster, students can draw 8 or 10 cm
diameter circles on the print instead of squares.
- Students will usually start slowly in their measuring but will quickly move
through the stars in their square. A fun option is to assign student groups
different sections of the cluster to plot. Or have a few groups do 5 cm squares
along the edges for the sake of comparison with other groups' results.
- The Jewelbox is a young cluster. It's age is only about 12 million years.
- It may increase students' interest to show slides of other star clusters
either before or after the activity. You can include open (otherwise known
as "galactic") clusters and globular clusters if you like. Also, a map of
Southern constellations to point out Crux and the location of the Jewelbox
helps to orient students.
- There are some obvious problems in the color designations for the stellar
classes on the StarGauge. In the end, however, almost all groups should
successfully arrive at the correct age of the Jewelbox.
- You might want to examine other clusters, like the Pleiades or Hyades. A good
color printer can be used to create good enough copies for a follow-up lab.
- The real name of the StarGauge is "flyspanker." It has been suggested
by many teachers that an alternate name be formulated to prevent the
snickers and other remarks that may erupt when students hear this term.
- Suggestions or comments about this activity should be sent to
[ Jewels of the Night Home Page
National Optical Astronomy Observatories, 950 North Cherry Avenue, P.O. Box
26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360