False color, near infrared image of the Kappa Andromedae star system as seen by the Subaru Telescope in Hawaii. Almost all of the light of the host star, on which the image is centered, has been removed through image processing.
Image: NAOJ / Subaru / J. Carson (College of Charleston) / T. Currie (University Toronto)
In a rare direct photo of a world beyond Earth, astronomers have spotted a planet 13 times more massive than Jupiter, the largest planet in our own solar system.
The planet orbits a star called Kappa Andromedae that is 2.5 times the mass of the sun and is located 170 light-years away from Earth. As a gas giant larger than Jupiter, it's classified as a "super-Jupiter."
The object is an interesting test case for theories of planet formation, scientists say. Based on observations of this system, the super Jupiter appears to have formed in the same way ordinary, lower-mass exoplanets do, by coalescing from a "protoplanetary disk" of material orbiting a nascent star.
That's because its orbit, somewhat wider than the path Neptune takes around our sun, is at a comparable distance to planetary orbits in the solar system. Additionally, its star, kappa Andromedae, is relatively young, at about 30 million years old (for comparison, the sun is roughly 5 billion years old). These clues point toward a formation story typical of smaller planets.
Previously, some scientists had doubted that such large stars could give birth to planets in protoplanetary disks. The new finding indicates that this star probably did just that.
The new photo was snapped by Japan's Subaru 8-meter telescope on the summit of Mauna Kea in Hawaii. Alien planets are extremely difficult to image directly because their stars are always so much brighter, and outshine any planets.
To capture this picture, astronomers looked in infrared light, and used a technique to hide the glare from the star in order to reveal the relatively faint dot of light from the planet. More than 800 planets have been discovered beyond the solar system, but only a handful so far have been imaged directly.
The discovery will be published in an upcoming issue of the Astrophysical Journal Letters.
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5 Comments
Add CommentIn the interests of accuracy. If this planet is actually about 13 times the mass of Jupiter it will only 'dwarf' Jupiter in terms of mass. A planet like this is going to be only about 10% larger in diameter due to the way in which planets reach equilibrium between their gravity and pressure forces.
Reply | Report Abuse | Link to thisSpeaking of dwarfs, as I understand, if it had been any more massive it would have been considered to be a brown dwarf star, possibly fusing deuterium at some point. What seems most curious to me is how such a large object might have accreted from the protoplanetary disk at the distance of Neptune, unless the diameter and mass of the disk was much larger than our own...
Reply | Report Abuse | Link to thiswould a first generation star with less heavy isotopes produce a system with just gas giants ? what if this giant was forming in the outer regions and as the solar wind pushed more gasses to the area , the giant became engorged and fell inward until it reach a stable orbit without headwind .
Reply | Report Abuse | Link to thisThat's an interesting thought, but as I understand lower metalicity population II stars are generally much older than population I stars like the Sun. This star is said to be only 170 light years from the Sun and, critically, is thought to be only 30 million years old.
Reply | Report Abuse | Link to thisIt seems that it's right on the cusp of being considered a brown dwarf.
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