View Full Version : Discussion: Cheap Method for Finding ...

2003-Nov-21, 09:33 PM
SUMMARY: Astronomers from the University of Texas at Austin believe they've figured out an inexpensive way to search for extrasolar planets. After stars like our own Sun use up their fuel they eventually turn into red giant stars, and then shrink again to become white dwarfs. Although the process will likely destroy the inner planets, the outer planets will probably still remain in orbit around the star. These white dwarfs are known to pulsate at a specific rate, so the gravity of a planet moving around the star should affect this pulse rate by a minute amount that should be detectable by inexpensive Earth-based telescopes.

Comments or questions about this story? Feel free to share your thoughts.

2003-Nov-21, 11:04 PM
I realise there is some great good in finding these planets for scientific knowledge purposes but ... what is the point in trying to find planets we are certain can't sustain life?

2003-Nov-21, 11:58 PM
You beat me to it Josh. I was about to say that this technique is all very well, but we really need to be developing techniques for finding earth-like planets.

2003-Nov-22, 07:54 AM
Fellas, you are both thinking with earth bias here. Life can exist on many different planets in many different forms.

2003-Nov-22, 08:32 AM
If life can exist on a planet orbiting a sun which has died then we might as well look for life ON the sun. Not an impossibility but also not where we expect to find life.

2003-Nov-22, 04:25 PM
I believe our understanding of the universe will improve all over by not limiting ourselves. Of course, if earthlike planets is what we want to find, then we should look elsewhere and with ther methods, but if we want to learn more about solar systems and how they change, we should try to understand solar systems in different stages.

Jack Lass
2003-Nov-25, 02:59 AM
Little bitty planets like ours and Venus, Mars and Mercury don't have enough mass to greatly effect their primaries. And since mass creates gravity our current means of detecting extra-solar planets through the wobbles they cause in their suns aren't sensitive enough to catch the tiny effects caused by any rocky bodies like ours.

That said, work is now ongoing on a follow-on to the Hubble that may be able to image such bodies directly around the nearest stars. That instrument, whose name escapes me for the moment, is scheduled to go into orbit and operation in, I believe, 2010. But the only way to reallly see such planets would be through the use on an optical interferometer with a virtual width approaching the size of Earth's orbit.

While this sounds like a tall order, it is readily possible that such an instrument, or a virtual analog of one, could be created using telescopic observation of certain stars at opposite sides of Earth's orbit. It would require some very precise time matching and a lot of computer power, but these will be well within reach by the time that the new space instrument goes into orbit.