Hektor family

Lore & Background

The Hektor family is a collisional asteroid family, meaning its members are fragments created by a collision with the original larger asteroid, 624 Hektor. All members share similar orbits as a result of that event. The family is part of the Jupiter trojan dynamical group, a set of asteroids that orbit about 60 degrees ahead of or behind Jupiter at the Lagrange points L4 and L5; the Hektor family resides in the L4 cloud, the Greek camp. Members of the Hektor family are both part of this wider Trojan dynamical group and physical fragments of 624 Hektor. All known members are dark D-type asteroids with albedos around 0.03–0.04. The family is considered non-catastrophic because 624 Hektor, its largest member, accounts for nearly all of the family's total mass, rather than being simply the largest among many fragments each making up a small fraction of the original destroyed asteroid. The age of the family is very poorly constrained due to the lack of known small members to model, with different methods of analysis suggesting ages of 1–4 billion years and 0.1–2.5 billion years.

Reader's Guide

The Hektor family's significance lies in its dual nature as both a collisional asteroid family and a component of the larger Jupiter trojan dynamical group. As a non-catastrophic family, it offers a rare example where the parent body, 624 Hektor, survived the collision largely intact, retaining most of the family's mass. This contrasts with typical asteroid families where the parent body is shattered into many small fragments. The family's location in the L4 Trojan cloud (the Greek camp) ties it to the broader population of Jupiter trojans, which are thought to be primordial bodies captured during the early solar system's evolution. The poor constraints on the family's age—ranging from 0.1 to 4 billion years depending on the method—highlight the difficulty of dating families with few small members, making the Hektor family a subject of ongoing study for understanding collisional processes and the history of the Trojan population. Its dark D-type spectral classification and low albedo are characteristic of primitive, carbon-rich material, linking it to the outer solar system's small-body reservoir.

Did You Know?

• The Hektor family is named for its largest member, 624 Hektor, which is 225 km across.
• All members of the Hektor family are dark D-type asteroids with albedos of about 0.03–0.04.
• The family is part of the Greek camp, the leading cloud of Jupiter trojans at the L4 Lagrange point.
• The family's age is poorly constrained, with estimates ranging from 1–4 billion years or 0.1–2.5 billion years.