## You Be the Astrophysicist

Find the mass of Cygnus X-1 |
Find the velocity of the galaxy M31 |
Find the diameter of HT Cas |

## You Be the Astrophysicist!

Science is a process of inquiry. Scientists propose hypotheses and test them with experiments. In these pages you will begin with several options for experiments that may lead to the answer you are seeking. Scientists go down many paths that turn out to be dead ends. In these pages, you will encounter some dead ends, too. But often a scientist learns much from a "dead end". You will find that is true here as well.

As you travel through the pages in the site to answer the question you are given, you will have the chance to read about relevant concepts in astronomy and test your skills with interactive quizzes. You should take the time to take the interactive quizzes. For each one that you successfully complete, you will be given a record at the end of skills and concepts you have learned. You will have the opportunity to take different paths and to try different techniques. Different paths are indicated by buttons as well as descriptions. Some buttons you will encounter (and what you will find there) include:

To get more information | |

To choose an experiment | |

To use calculations and tools | |

To look at some data | |

To take a quiz |

**Important:**When you encounter a quiz to test what you have learned, always press the "check me" button to check your answer and proceed (rather than pressing the return button). By taking the quizzes, you will generate a list of concepts you have learned by exploring these problems.

**Teachers:**If you like, you can ask students to print out the final page, which contains a list of new skills or concepts the student has mastered in his or her journey. Many of these skills correspond in some way to National Science or Math standards. Thus these printouts can be used as an assessment tool for this activity.

As always, we appreciate your comments about these projects.

Now you can choose an astronomy question to solve from the list below:

Find the mass of Cygnus X-1 | |

Find the velocity of the galaxy M31 | |

Find the diameter of HT Cas |

try your hand at analyzing actual data.

Check out Hera.