Astronomy Applets

How do stars form? This short film will explain with very cool graphics.

This Applet will demonstrate how quickly stars evolve off the main sequence depending on their initial position.

This applet represents the solar system, including the four major moons of Jupiter and our own, and a couple of comets.

This is an animation showing the geometry of Earth, Moon, and Sun that gives us the differing phases of the Moon.

The determining factor in the life of a star is its mass. The more massive a star the greater its energy output and the faster it evolves (changes). The about figure shows the temperature-luminosity relation for stars. This is known as the the Hertzsprung-Russell diagram. Stars on the main-sequence generate energy by converting (via fusion) hydrogen into helium. As stars use up their hydrogen fuel, they evolve off the main-sequence into the giant or supergiant phase. During these stages stars may "burn" helium or other even heavier elements as the core of the star reaches higher and higher temperatures and densities. How far this process proceeds depends on the initial mass of the star. The lowest mass stars will never go beyond hydrogen burning while the highest mass stars can produce elements all the way up to iron in their cores.

Allows you to set the masses, orbital separation, orbital eccentricity, the inclination angle to our line of sight, and the angle of the nodes of an orbiting star pair. You see the privileged (from above the orbit) and the earth view of the system (which depends on the inclination angle). The observed velocities of the two stars, and the Doppler shifted spectral lines (as seen against the combined continuum from the two stars) are also shown in the upper right box. The spectral lines associated with each star are indicated and the unshifted line positions are also marked. The movement of the spectral lines against the continuum has been greatly exaggerated for display purposes, and the difference in brightness of the two stars has been ignored.

Orbiting stars which are separated by a small distance may pass in front of one another. It is not possible for astronomers to see the individual stars, but there will be a change in the total light coming from the two stars when they "eclipse" one another. This simulation shows how this eclipse happens.

The Ultimate Resource for Eclipse Photograpy... after all, his name is Mr. Eclipse.

Take a look around, some are very fun

webmaster: Laura Davies
Updated: 09.25.05