No Evidence for Orbital Clustering in the Extreme Trans-Neptunian Objects

The apparent clustering in longitude of perihelion pi and ascending node Omega of extreme trans-Neptunian objects (ETNOs) has been attributed to the gravitational effects of an unseen 5-10 Earth-mass planet in the outer solar system. To investigate how selection bias may contribute to this clustering, we consider 14 ETNOs discovered by the Dark Energy Survey, the Outer Solar System Origins Survey, and the survey of Sheppard and Trujillo. Using each survey's published pointing history, depth, and TNO tracking selections, we calculate the joint probability that these objects are consistent with an underlying parent population with uniform distributions in pi and Omega. We find that the mean scaled longitude of perihelion and orbital poles of the detected ETNOs are consistent with a uniform population at a level between 17% and 94% and thus conclude that this sample provides no evidence for angular clustering.

Automated summary

The apparent clustering in longitude of perihelion and ascending nodes of extreme trans-Neptunian objects (ETNOs) has been attributed to the gravitational effects of an unseen planet in the outer solar system. However, analysis of 14 ETNOs does not provide evidence for angular clustering, suggesting that the detected objects are consistent with a uniform population distribution.