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Gravity-Bent Starlight Reveals a New Planet

dfab writes "The first experimental proof of Einstein's general theory has been revamped to discover planets around distant stars. Yesterday astronomers announced that a new technique called gravitational microlensing has found a star that hosts a roughly Jupiter-sized planet in a roughly Jupiter-sized orbit by observing its effect on the light from a bright star beyond that planetary system. See the NASA report or the gory details."

4 of 26 comments (clear)

  1. More Info by mizidymizark · · Score: 5, Informative

    Space.com also had an article about this yesterday. It gives a little better timeline to when it will be available to check low mass stars in the future, as well as doing a comparision on other extrasolar planetary detection techniques.

  2. How it works by GlobalEcho · · Score: 4, Informative

    For those who want a quick excerpt of the science:

    Gravitational microlensing uses a distant star (or other massive object) to bend light the same way as a lens would. If that star is perfectly aligned with an even more distant star (from our perspective) then the lens will call the more distant star to brighten, at least for as long as the alignment lasts.

    The brightening comes with a spike (from "caustics" which are like irregularities in the lens), as the alignment gets good and them bad again. If you see a second, smaller spike, or an unusual extra image, that's evidence of a planet.

    I'm not sure how you distinguish planets from weird caustics.

    Note: this technique is good for detecting planets with long-period orbits, whereas the doppler-shift techniques are lousy for that, because they only work if the planet's revolution period is small (like in days).

  3. Re:What happened to the original experiment? by Tango42 · · Score: 3, Informative

    Not that experiment. The one they are refering to is the one about watching stars during solar eclipses, and they are in the wrong place due to the sun's gravity bending the light. The one you are thinking of it completely different, and is about frame-dragging.

  4. Re:What happened to the original experiment? by Mercenary_56 · · Score: 3, Informative

    Ummm, I'm guessing you are referring to Gravity Probe B?

    Not only is it going to take 1-2 years to test the theory, it hasn't been launched yet. It's new\rescheduled launch date isn't till April 19, 2004.

    So to answer your question of what happened to the results??

    It's hard to give results on a project that hasn't been launched yet.

    Read more about this project here.

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