The tables below provide equivalences for some of the more common units you may encounter in this course.

Unit | Symbol | Metric Equivalent | Used for |
---|---|---|---|

Angstrom | 10^{-10}m |
Atomic physics; Spectroscopy | |

Earth Radius | 6.378 x 10^{6}m |
Planetology | |

Solar Radius | 6.96 x 10^{8}m |
Stellar astronomy | |

Astronomical Unit | AU | 1.496 x 10^{11}m |
Solar system astronomy |

Lightyear | ly | 9.46 x 10^{15}m |
Interstellar & intergalactic astronomy |

Parsec | pc | 3.09 x 10^{16}m |
Interstellar & intergalactic astronomy |

Unit | Symbol | Metric Equivalent | Used for |
---|---|---|---|

Earth Mass | 5.98 x 10^{24}kg |
Planetology | |

Solar Mass | 1.99 x 10^{30}kg |
Stellar and galactic astronomy |

Unit | Symbol | Metric Equivalent | Used for |
---|---|---|---|

Solar Luminosity | 3.90 x 10^{26}Watts |
Stellar and galactic astronomy |

Luminosities are also measured in terms of absolute magnitude. This is not a unit of measurement

Chris Dolan at the University of Wisconsin - Madison Astronomy Department has a JavaScript Astrophysical Calculator that includes astrophysical constants and planetary data that you may find useful if you need to do any calculations with these numbers.

- Be sure to check out my handy table of Metric Prefixes
- To return to the main astronomy page, click here.