Blog

What is an astronomical unit? 

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation? 

What would happen inside the Sun if a slight rise in core temperature led to a rapid rise in fusion energy?

This figure shows idealized thermal radiation spectra from several stars and a human. Based on this graph, at about what wavelength does a 15,000 K star emit its most intense light?

LIGO detected gravitational waves that probably originated from:

The fact that the Voyager spacecraft continue to speed out of the solar system, even though its rockets have no fuel, is an example of 

If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits 

What is the main idea captured by this graph?

Study this H-R diagram. Which of the following stars is the largest in size (radius)? (The red arrows help you locate these stars on the diagram.)

The angular resolution of a telescope is never less than its diffraction limit.