> Although Kepler was designed to find transiting planets, this planet was not identified using the transit method. Instead, it was discovered using a technique first proposed by Avi Loeb of the CfA and his colleague Scott Gaudi in 2003.
> The new method looks for three small effects that occur simultaneously as a planet orbits the star. Einstein’s “beaming” effect causes the star to brighten as it moves toward us, tugged by the planet, and dim as it moves away. The brightening results from photons “piling up” in energy, as well as light getting focused in the direction of the star’s motion due to relativistic effects. “This is the first time that this aspect of Einstein’s theory of relativity has been used to discover a planet,” said co-author Tsevi Mazeh of Tel Aviv University.
I’ve personally found new planets in transit data from Kepler. The effect mentioned would be absolutely tiny. I hesitate to say impossible to detect, but to get any significant brightening the star would have to be moving radially at some percentage of the speed of light which, given that the planet has a small mass then the star is exceedingly unlikely.
> The team also looked for signs that the star was stretched into a football shape by gravitational tides from the orbiting planet. The star would appear brighter when we observe the “football” from the side, due to more visible surface area, and fainter when viewed end-on. The third small effect was due to starlight reflected by the planet itself.
These two would operate together. There are thousands of regular periodic variable stars in the Kepler data. Such a variation would just look like a normal variable star.
> Once the new planet was identified, it was confirmed by Latham using radial velocity observations gathered by the TRES spectrograph at Whipple Observatory in Arizona, and by Lev Tal-Or (Tel Aviv University) using the SOPHIE spectrograph at the Haute-Provence Observatory in France.
That’s very interesting. I was told that there was no star in the Kepler dataset that was bright enough to check for planets by spectral methods. Looks like I was told wrongly.
> A closer look at the Kepler data also showed that the planet transits its star, providing additional confirmation.
Why not look for that first, it would have been easier. Pity though. It would have been better if they had succeeded in using Kepler data to find a planet that did not transit its star, confirmed by spectral methods.
> “Einstein’s planet,” formally known as Kepler-76b, is a “hot Jupiter” that orbits its star every 1.5 days. Its diameter is about 25 percent larger than Jupiter and it weighs twice as much. It orbits a type F star located about 2,000 light-years from Earth in the constellation Cygnus. The planet is tidally locked to its star, always showing the same face to it, just as the Moon is tidally locked to Earth.