'The outer solar system probably does not contain a large gas giant planet, or a small, companion star,'
-Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.
Tyche is the hypothetical gas giant that was proposed to be causing mass extinctions on Earth as well as certain cometary influxes. Unfortunately, as new data shows, he may not exist. On 7 March 2014, NASA reported that the WISE telescope had ruled out the possibility of a Saturn-sized object at 10,000 AU, and a Jupiter-sized or larger object out to 26,000 AU. However, as I mentioned many months ago, The Planet X-based mass extinction theories were somehow ruled out even prior to the new WISE study. Meanwhile, the team admits their research was not wasted - and says they found several thousand new residents in our sun's 'backyard,' consisting of stars and cool bodies called brown dwarfs. 'Neighboring star systems that have been hiding in plain sight just jump out in the WISE data,' said Ned Wright of the University of California, Los Angeles, the principal investigator of the mission. The second WISE study, which concentrated on objects beyond our solar system, found 3,525 stars and brown dwarfs within 500 light-years of our sun. 'We're finding objects that were totally overlooked before,' said Davy Kirkpatrick of NASA's Infrared and Processing Analysis Center at the California Institute of Technology, Pasadena, Calif. Kirkpatrick is lead author of the second paper, also in the Astrophysical Journal. Some of these 3,525 objects also were found in the Luhman study, which catalogued 762 objects. The discovery of the new stars is something of a consolation prize for those who had hoped that Planet X would be discovered in the sweep which was resumed last September after a two-year hibernation. Some researchers believed there was another celestial body known as Planet X – as well as Nemesis or Tyche – somewhere in the outer solar system. It was believed that this mysterious large planet or small star might periodically sweep thorugh bands of outer comets sending them flying towards earth. But its existence now seems unlikely according to Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University. "The outer solar system probably does not contain a large gas giant planet, or a small, companion star," he said.
But although Tyche may not exist, there still is another another candidate for ninth planet status-Planet X 2.0. he Kuiper belt terminates suddenly at a distance of 48 astronomical units (AU) from the Sun (by comparison, Neptune lies 30 AU from the Sun), and there has been some speculation that this sudden drop-off, known as the "Kuiper cliff", may be attributed to the presence of an object with a mass between that of Mars and Earth located beyond 48 AU. Computer simulations by Patryk Lykawka of Kobe University have suggested that a body with a mass between 0.3 and 0.7 that of the Earth, ejected outward by Neptune early in the Solar System's formation and currently in an elongated orbit between 101 and 200 AU from the Sun, could explain the Kuiper cliff and the peculiar detached objects such as Sedna. While some astronomers have cautiously supported these claims, others have dismissed them as "contrived".