Are there other super-Earths in the outer Solar System?
The Outer Solar System Origins Survey (OSSOS) is a search for faint objects at the outskirts of our Solar System, beyond the orbit of Neptune. Since 2013, the survey has been running on the Canada France Hawaii Telescope, exploring the outer Solar System and discovering distant objects such as the new dwarf planet announced in 2016.
Recently the OSSOS team has examined its results for independent evidence of the signal of orbital alignment used to argue for an additional very massive planet. This planet, known by many as "Planet 9", is thought to be several times larger than Earth and located in the outer Solar System. Previous works have suggested that the distribution of orbit orientations of TNOs (trans-Neptunian objects) is clustered, most likely due to the presence of another large planet. Though, it was acknowledged that the previous surveys have detected the objects on those orbits in a biased fashion, perhaps enhancing the clustering.
Because OSSOS was designed to be exquisitely calibrated, it becomes the tool to test precisely just how biased the previous surveys were. The team found that when bias is taken into account, the OSSOS data is consistent with no intrinsic clustering at all in the outer Solar System - and therefore calling into question the need for an additional large planet.
This is part of the thesis work by UBC Physics & Astronomy alumnus and University of Victoria PhD student Cory Shankman (under the supervision of Dr. JJ Kavelaars of the University of Victoria and the National Research Council of Canada). Dr. Brett Gladman of UBC Physics & Astronomy is a lead investigator of OSSOS.
For more information:
- Visit the OSSOS web site
- Read the Globe and Mail cover story "Canadian-led study casts doubt on existence of Planet Nine"
- Read the publication "OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects"
Professor Brett Gladman
UBC Dept of Physics and Astronomy