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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."
...failed. Eddington's measurements were flawed, and the good ones weren't good enough. He was lucky. His unsupportable "result" was correct.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
This image from the "gory details" gives you a quick understanding of what they mean. Pretty cool that they use one star to see the planet around another star.
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.
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).
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.
Interesting. I had the idea that some star was being used to help focus light from the planet, acting as a gravitational lens and giving us a better view of the planet.
Instead, the planet is lensing some star beyond it, and then (later) so is the star that planet is around, as the planet+star moves past the object being focused.
This shows up as two sharp spikes in the brightness of the star over time (I guess one on each side of the planet, imperfectly aligned?) and one broader curve as it passes the star. The shape of the curves tell you how massive the planet and star are.
It looks like it's about Jupiter's size and a bit nearer in than Jupiter. That's comforting; thus far the only planets we ever seem to detect are bigger than Jupiter and closer than Mercury, which really boggles my mind. This system looks a lot more like ours.
Neat. What will those clever astrophysicists think of next.
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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