Planet Found in Quadruple Star System
Once again the compulsive real universe upstages science fiction. Imagine Luke Skywalker watching four stars setting in the evening: a white hot globe, its diminutive red companion, and a pair of brilliant stars in the background that look like an apparition of a double Venus.
That’s the view from an obscure system of four co-orbiting stars where a gas giant planet has been found. It sets the record for the first quadruple stars system where a transiting planet – and presumably many more – is known to exist.
The gas giant whirls around a tight binary system consisting of a red dwarf and a star slightly hotter than our sun. The two stars complete an orbit about each other once every 20 days.
The other pair of stars, which are a sun-like star and red dwarf, are separate from the planet’s binary stars by a whopping 800 billion miles (or slightly over 100 solar system diameters as measured out to the radius of Neptune’s orbit).
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Volunteers searching the publicly available Kepler data as part of the Planet Hunters citizen science project discovered the planet. The project uses human pattern recognition via the World Wide Web to identify the unique light curves recorded by NASA's Kepler space telescope as an object passes in front of a star. Message boards enable volunteers to discuss and analyze interesting Kepler light curves from numerous observations.
Once the planet was identified it was confirmed by spectroscopic observations at the Keck observatory to measure the stellar wobble induced by the small gravitational pull of the planet.
The accompanying binary system was then discovered in residual anomalous stellar motion. This yielded telltale evidence for the pull of the distant binary. The faint duo was then visually found with Keck (photo below of the entire quad system).
Though the planet is gaseous, at half the mass of Jupiter, it could conceivably have large moons like Saturn's moon Titan. But at oven-roasting surface temperatures of 500 degrees Fahrenheit, any moons would be pretty toasty and waterless. The planet is slightly closer to the binary than Venus is too our Sun.
If anyone lived on such a moon, they would routinely see transits and eclipses of the the red dwarf and its brighter companion. Depending on orbital positions, the second, far distant stellar pair, would illuminate the night.
At an estimated age of no more than 2 billion years, the system is too young for intelligent life to exist. What’s more, the unusually rapidly spinning hot white star will burn out in just a few billion years. The red dwarf will feed off the larger companion as it swells ever bigger in its final years.
If intelligent life were to arise there billions of years from now, long after the stellar fireworks, the beings would behold a brilliant icy white dwarf and red dwarf in the daytime sky.
What makes this stellar grouping the stuff of science fiction is that at some point in the far future it is conceivable there could be at as many as three inhabitable planets or moons scattered in the system. The one binary that has two widely separated stars might posses two independent planetary systems.
If so, it is conceivable that space faring civilizations could each arise around the sun-like star, and red dwarf. Once space travel is achieved, they could physically come in contact with each other, assuming the biologies aren't so different that planet visitation isn’t practical.
A civilization at the wide binary pair would eventually make the very long journey to the other binary system where the newly discovered planet dwells. the planets in this companion system would have greatly cooled off following the demise of their white-hot star.
This quadruple system system potentially has a variety of worlds and resources to yield a true Star Trek like civilization that make space faring between inhabited worlds among the binaries as common as the great age of ocean exploration.
Image Credit: NASA, E. Schwamb