Astronomers think they have taken the first picture ever of a planet orbiting a star very similar to our own sun. However, the new planet itself appears to be quite different from our Earth. Located around 500 light-years from Earth, the planet in the snapshot is around eight times bigger than Jupiter, the biggest in our solar system and lies more than ten times further from its star than the sun does from Neptune [Telegraph]. Researchers were surprised to discover that the planet orbits at such a distance from its star, and say the discovery could upend accepted theories of planet formation.
The researchers say they’ll keep studying the object they spotted to confirm that the planet is in fact orbiting around the star, as opposed to the possibility, however unlikely, that the two objects just happen to lie in the same area of the sky at roughly the same distance from us. “Of course it would be premature to say that the object is definitely orbiting this star, but the evidence is extremely compelling,” [lead researcher David] Lafrenière said [SPACE.com].
While researchers have previously discovered over 300 “exoplanets,” or planets orbiting stars beyond our solar system, this is the first image of an exoplanet orbiting a sun-like star; previous exoplanets have either been spotted floating freely through space, independent of any star, or orbiting the dimmer brown dwarf stars. According to the study, which was posted online in advance of publication, the star that this supposed planet revolves around is similar in mass to our sun, but is much younger–about 5 million years old, as opposed to our sun’s age of 4.5 billion years.
The planet’s distance from its star poses a riddle for scientists. Previously, researchers believed that the dust, ice, and gas that form into planets are concentrated in tight disks around newborn stars, and that there wouldn’t be enough mass to form a planet at such a far distance from the star. Which raises the question, “if this object really is what they think it is, what the hell is it doing out there,”330 [astronomical units] from the star, says theorist Alan Boss…. One possibility is that the planet formed much closer to the star and then got kicked out, either through gravitational interactions with other planet-forming material in what would have been an unusually large disk, or through the gravity of an as yet undetected massive planet [Science News].
For more details, and a hefty dose of science excitement, go to Phil Plait’s blog post, “PLANET IMAGED AROUND A SUNLIKE STAR?!”
Image: Gemini Observatory