Page 1 of 1

Stellar parallax for stars near the ecliptic.

Posted: 20.07.2006, 22:23
by Nick
It just occured to me that stars near the plane of the ecliptic, even very near stars, wouldn't have a very pronounced parallax as the Earth orbits the Sun. Were astronmers only able to get accurate distance measurements of stars closer to the celestial poles before the Hipparcos sattelite?

Posted: 20.07.2006, 22:46
by Hamiltonian
No reason why they couldn't get a parallax near the ecliptic.
The Earth still moves from one side of the sun to the other relative to the star. The star will just look as if its moving back and forward in a line instead of making a little circle in the sky.
Draw a picture of the circle of Earth's orbit and the star off to one side, and you'll see that a parallax is still possible to measure.

Posted: 20.07.2006, 22:54
by Nick
Dude, that totally makes perfect sense. I thought I might be missing something...

I guess that's the end of this thread. :)