Schubart family

Lore & Background

The Schubart family is a group of physically related asteroids created by a collision with an original larger asteroid, with the fragments continuing on similar orbits. It lies within the Hilda dynamical group, which consists of asteroids in a 3:2 orbital resonance with Jupiter. Unlike a dynamical group, whose members share orbits only due to gravitational interactions, the Schubart family members are fragments of a single original body. The family is considered catastrophic because its largest member, 1911 Schubart, does not hold a majority of the family's mass. All members are dark P-type asteroids with albedos around 0.04. The family is fairly old, with an estimated age of 1.7±0.7 billion years, though the Hilda collisional family in the same region is much older, possibly 4 billion years.

Reader's Guide

The Schubart family's significance lies in its status as a well-defined collisional family within the Hilda dynamical group, illustrating the distinction between families formed by physical breakup and groups formed by gravitational resonance. With at least 353 known members, it provides a substantial sample for studying the outcomes of catastrophic collisions in the outer main belt. Its age of 1.7±0.7 billion years, while old by typical asteroid family standards, is younger than the nearby Hilda family, offering a comparative timeline for collisional evolution in the same orbital region. The family's dark P-type composition and low albedo of 0.04 are characteristic of primitive, carbon-rich material, linking it to the early solar system's composition. As a catastrophic family, it demonstrates that the original parent body was thoroughly disrupted, leaving no single fragment dominant in mass. This makes the Schubart family a key object for understanding the long-term collisional history of the Hilda region and the processes that shape asteroid populations over billions of years.

Did You Know?

• The Schubart family contains at least 353 known asteroids.
• Its largest member, 1911 Schubart, is 67 kilometres across.
• The family is estimated to be 1.7±0.7 billion years old.