Exoplanetary Systems
Exoplanetary Systems
Goals: Discuss the discovery and distribution of extrasolar planets.
Before starting, turn on: stars, mwVis, constel, 10ly
You will be using: expl, textcment command
Last we left you, your were orbiting the Sun from about 20 light-years away. Now let's explore those stars that have confirmed planetary systems, the exoplanets. The first exoplanet, around 51 Pegasi, was discovered in 1995. Since then, astronomers have been uncovering planetary systems all over the sky. For more on how these are found, please see our description of this data group in “Extrasolar Planets.”
Turn on the expl group and pull out a bit to see them in perspective. Each of these blue rings encircles a star that is host to one or more planets. If you orbit the Sun, you will notice that they are all huddled around the Sun. This is an observational bias since, for the majority of exoplanetary systems, we see the effects of the planets only on nearby stars. For a few detection techniques like pulsar timing and lensing, astronomers can actually see planetary systems to great distances. But mostly they are seeing the wobbling of the star from its spectrum and do not actually see the planets themselves. Now that you've flown from the Solar System to about 100 light-years away, perhaps you have a better appreciation for the challenges involved in seeing planets from such distances.
If you see the exoplanets fading from view, feel free to “slum” them up using the Slum Slider. The rings will grow as you increase the luminosity scale factor. If you find the labels are fading from view or prefer a stronger color to the blue, you may change the label color by using the textcment command. Change the labels to a gray color by using the command
textcment 1 .3 .3 .3This changes color index 1 to a red-green-blue color of 0.3.
Next we'll see how many of these exoplanets have heard from us when we discuss the extent of Earth's radio signals in space.
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott