astralavista

Caltech planetary scientist Maciej Konacki has discovered the first planet that never sleeps. The Jupiter-sized planet in the constellation Cygnus belongs to a complex solar system dominated by three different suns. And while multiple stars have been known to circle around each other, astronomers have never seen a planet in such company.
The discovery raises serious questions about what we know about planet formation, a topic frequently discussed on this blog (see previous post.)
Here's why: Latest planet formation theories propose that planets coalesce from a wide protoplanetary dust disks, circling stars much like Saturn's rings. Newborn planets are then pulled inwards towards the parent star. Some are gobbled up by it, some are flung into space like a rock from a sling by the star's gravity, and some settle in stable orbits.
However, theory says, if the parent star is part of a multi-stellar system, the dusk disk formation gets disrupted by the competing gravitational pulls of the different stars, the disk grows too narrow, and planet formation breaks down.
"How that planet formed in such a complicated setting is very puzzling," Konacki said about his discovery. "If we believe that the same basic processes lead to the formation of planets around single stars and components of multiple stellar systems, then such processes should be equally feasible, regardless of the presence of stellar companions. Planets from complicated stellar systems will put our theories of planet formation to a strict test."
The system is about 149 light-years from Earth. The stars are about as close to one another as the distance between the Sun and Saturn.
"In other words, a viewer there would see three bright suns in the sky," Caltech said in a press release. "In fact, the sun that the planet orbits would be a very large object in the sky indeed, given that the planet's "year" is only three and a half days long. And it would be yellow, because the main star of HD 188753 is very similar to our own sun. The larger of the other two suns would be orange, and the smaller red."
Said Konacki: "The environment in which this planet exists is quite spectacular. With three suns, the sky view must be out of this world-literally and figuratively."

Image: This artist's animation shows the view from a hypothetical moon in orbit around the first known planet to reside in a tight-knit triple-star system. Credit: Nasa