My Cart (0)

Message from Sky & Telescope

The AAS staff (including staff of Sky & Telescope) are working remotely from their homes to support the social distancing efforts to contain COVID 19. While we are all working to support the S&T community, there may be delays in responding during this time. If you have a question or concern, please contact Camillia Taylor at [email protected]. Click here for information on delays in international deliveries.

This is a difficult time for the entire United States. Aero, our fulfillment partner, is based in Ohio. Aero provides fulfillment services for P&G. While they will continue to fulfill our orders, there may be a delay in shipping our products because they must give priority to medical, personal healthcare, and cleaning and sanitization products.

Lab Exercises in Astronomy: The Earth's Orbital Velocity

By The Editors of Sky & Telescope

Format: Supplies

SKU# LE005

We all know Earth orbits the Sun, right? But what's the actual evidence? In this lab, the student will work directly with detailed spectra of Arcturus, taken six months apart, measur the Doppler shift of spectral lines in these spectra, and determine Earth's velocity.

On two high-dispersion spectrograms of Arcturus taken six months apart, the positions of selected absorption lines are measured accurately. In one case the lines are shifted to the violet (shorter wavelengths) as the Earth approaches the star; in the other case they are shifted to the red. These Doppler shifts are measured to 0.1 millimeter and calculations made to obtain the star’s motion related to the Sun, the Earth’s orbital velocity, and the Earth’s distance from the Sun. As many as seven lines can be measured, increasing the accuracy of the results. Prepared by Darrel B. Hoff.

Author The Editors of Sky & Telescope
Format Supplies

In Stock

Be the first to review this product