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General Category => Astronomy & Science => Topic started by: blotz on February 21, 2013, 04:34:32 PM

Title: Kepler
Post by: blotz on February 21, 2013, 04:34:32 PM
kepler finds planets by measuring the ammount of light the star is-wat's the right word- 'exporting', and measuring if the light level is constant, and if it isn't that means there's a planet

BUT then how do they find binary stars? they just see 2 stars orbiting around each other? but when i checked their webstie, it said "eclipsing binary stars" so is it like they see that the star's light level goes up and they know it's a binary star???

just need-a clarify

otherwise, this thread is about Kelper
Title: Re: Kepler
Post by: atomic7732 on February 21, 2013, 05:28:41 PM
If you've ever seen the kepler light curves... they're anything but constant. From any star.

Non-eclipsing binary stars have the same light curve, if their angular separation is smaller than the resolution of the circle the algorithms and programs 'look' inside for that particular 'star'.

Eclipsing binaries have fun light curves...

(http://spacespin.org/mediagallery/mediaobjects/orig/d/d_omc-eclipsing-binaries-ligh.jpg)

And shutter effect...

(http://ph-images.s3.amazonaws.com/APH72064522.jpg)
(http://ph-images.s3.amazonaws.com/APH41124814.jpg)
(http://ph-images.s3.amazonaws.com/APH73139274.jpg)

Basically all it is is two (or maybe more) stars orbiting in the same plane so that we can see the stars alternatingly pass in front of the other. Depending on the difference in brightness the dips may be the same or they may alternate in depth, with the smaller one meaning the brighter star is passing in front of the dimmer one. Even though it is brighter, when a star is not eclipsed, Kepler (or anything using photometry) detects the light from both stars.