Kepler Spies A Third Neptune Sized World, Transiting A Binary Star System, About 4,000 Light Years Away, In Cygnus...

This would be a truly beautiful sight to see: a larger and smaller pair of stars, tightly orbiting one another -- in a swiftly evolving dance -- while large graceful gas giants float at a distance, slowly rotating and observing the pair's pirouettes.

Here's all that, from NASA this morning:

. . .Astronomers have discovered a third planet in the Kepler-47 system, securing the system’s title as the most interesting of the binary-star worlds. Using data from NASA’s Kepler space telescope, a team of researchers, led by astronomers at San Diego State University, detected the new Neptune-to-Saturn-size planet orbiting between two previously known planets.

With its three planets orbiting two suns, Kepler-47 is the only known multi-planet circumbinary system. Circumbinary planets are those that orbit two stars.

The planets in the Kepler-47 system were detected via the “transit method.” If the orbital plane of the planet is aligned edge-on as seen from Earth, the planet can pass in front of the host stars, leading to a measurable decrease in the observed brightness. The new planet, dubbed Kepler-47d, was not detected earlier due to weak transit signals. . . .

With the discovery of the new planet, a much better understanding of the system is possible. For example, researchers now know the planets in in this circumbinary system are very low density – less than that of Saturn, the Solar System planet with the lowest density.

While a low density is not that unusual for the sizzling hot-Jupiter type exoplanets, it is rare for mild-temperature planets. Kepler-47d’s equilibrium temperature is roughly 50 degrees F (10 degrees C), while Kepler-47c is ‑26 degrees F (‑32 degrees C). The innermost planet, which is the smallest circumbinary planet known, is a much hotter 336 degrees F (169 degrees C). . . .

Onward, grinning. Be excellent to one another.

नमस्ते