Hubble Finds a Massive ExoPlanet 9 Times the Size of Jupiter @TheCosmosNews
#thecosmosnews Hubble Finds a Planet Forming in an Unconventional Way NASA s Hubble Space Telescope has directly photographed evidence of a Jupiter-like protoplanet forming through what researchers describe as an "intense and violent process." This discovery supports a long-debated theory for how planets like Jupiter form, called "disk instability." The new world under construction is embedded in a protoplanetary disk of dust and gas with distinct spiral structure swirling around surrounding a young star that’s estimated to be around 2 million years old. That s about the age of our solar system when planet formation was underway. (The solar system s age is currently 4.6 billion years.) "Nature is clever; it can produce planets in a range of different ways," said Thayne Currie of the Subaru Telescope and Eureka Scientific, lead researcher on the study. All planets are made from material that originated in a circumstellar disk. The dominant theory for jovian planet formation is called "core accretion," a bottom-up approach where planets embedded in the disk grow from small objects – with sizes ranging from dust grains to boulders – colliding and sticking together as they orbit a star. This core then slowly accumulates gas from the disk. In contrast, the disk instability approach is a top-down model where as a massive disk around a star cools, gravity causes the disk to rapidly break up into one or more planet-mass fragments. The newly forming planet, called AB Aurigae b, is probably about nine times more massive than Jupiter and orbits its host star at a whopping distance of 8.6 billion miles – over two times farther than Pluto is from our Sun. At that distance it would take a very long time, if ever, for a Jupiter-sized planet to form by core accretion. This leads researchers to conclude that the disk instability has enabled this planet to form at such a great distance. And, it is in a striking contrast to expectations of planet formation by the widely accepted core accretion model. The new analysis combines data from two Hubble instruments: the Space Telescope Imaging Spectrograph and the Near Infrared Camera and Multi-Object Spectrograph. These data were compared to those from a state-of-the-art planet imaging instrument called SCExAO on Japan s 8.2-meter Subaru Telescope located at the summit of Mauna Kea, Hawaii. The wealth of data from space and ground-based telescopes proved critical, because distinguishing between infant planets and complex disk features unrelated to planets is very difficult. Source:NASA