(612911) 2004 XR190

(612911) 2004 XR190, also known as "Buffy", is a trans-Neptunian object (TNO) classified as a detached object. It was discovered on December 11, 2004, by Andrew C. Becker, Andrew W. Puckett, and Jeremy M. Kubica at the Apache Point Observatory in Sunspot, New Mexico.

As a detached object, (612911) 2004 XR190 possesses a highly eccentric orbit that keeps it far from Neptune, preventing significant gravitational interactions with the planet. This detachment distinguishes it from objects in resonant orbits (like Plutinos) and scattered disc objects that have closer encounters with Neptune.

The orbital characteristics of Buffy are notable. Its semi-major axis is approximately 61.6 AU, and it has an orbital period of around 480 years. The object's relatively low eccentricity (around 0.24) for a detached object means its distance from the Sun varies less than some other TNOs. Its inclination to the ecliptic is approximately 47 degrees, which is relatively high compared to many other Kuiper belt objects.

Buffy's size is estimated to be around 500-800 kilometers in diameter, making it a candidate dwarf planet according to some size-based definitions. However, further observations and analyses, particularly of its albedo and density, are needed to determine if it meets the strict requirements for official dwarf planet status.

The discovery of (612911) 2004 XR190 contributed to a better understanding of the outer Solar System's population and formation. Its detached nature raised questions about the mechanisms that placed it in its current orbit. Proposed explanations include past gravitational interactions with hypothetical undiscovered planets, or early migration and ejection events during the Solar System's formation.

Further research on Buffy and other detached objects continues to refine our models of the dynamical evolution of the outer Solar System.