H-R Diagram - Overview
Project Description
Students create Hertzsprung-Russell (H-R) Diagrams, one of the most important
types of plots in astronomical research. H-R Diagrams are used to study the life
cycles of stars; the diagrams plot some measure of a star's luminosity against
some measure of the star's temperature. Toward the end of the project, students
use NVO tools to request a dataset containing thousands of stars, and use these
data to make an H-R diagram.
Concepts
- Stars have predictable life cycles that can be studied using a Hertzsprung-Russell (H-R) Diagram
- H-R Diagrams are made using observable measures of a star's luminosity and temperature,
such as absolute magnitude and color
- Stars near the Sun form a good random sample of stars
- Distances to other stars can be measured with parallax
- Modern astronomers use computers to search through large datasets
- Students can use the tools of professional astronomers to do real research
Target Audience
Advanced high school astronomy classes or Astronomy 101 level classes. With a bit more
teacher support, the project can be used with higher-level college classes such as
Stellar Astrophysics.
Classroom Time
You can teach the project in about six 45-minute classroom sessions, depending
on student understanding. If students have not seen H-R diagrams previously, spend
one class session explaining the diagrams, and how they relate to stellar evolution.
Spend one session on Exercise 1, the diagram of the brightest stars, and the associated
questions. Spend one session on the diagram of the nearest stars and the combined
schematic diagram.
Spend one session on measuring distance with parallax and on searching the NVO
registry for metadata and data useful for making an H-R diagram. Spend one session having
students download data using VizieR and analyze the data using a graphing program. Finally,
spend one session helping the students understand the final H-R diagram they created, and
how it relates to stellar evolution.
If your class will do this in a lab, allow about two three-hour lab sessions. The
project can also be assigned as a self-paced homework project over about two weeks.
Real World Relevance
This project teaches students about H-R diagrams, one of the key components in our
understanding of stellar evolution.
The project should also help students experience a new way of doing astronomy research.
Astronomers today spend much of their time online, searching through observations
that other astronomers have made. This project allows students to take the role of
astronomers, using professional tools to conduct real astronomy research.
Sample Solutions
Click the link below to download sample solutions for the project. To see the answers, you must have
the Adobe Acrobat PDF viewer installed on your computer. Acrobat is available for
free download at Adobe's
web site.
Remember that this page is visible to your students, so plan accordingly. (We plan
to set up a password-protected system for solutions in the near future.) If you
are a student posing as a teacher to see the solutions, the karma police will get
you.
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