Haffner 16: A Young Moving Group in the Making

TL;DR

Haffner 16 is a young, dynamically evolving star cluster with a rich pre-main sequence population, shedding low-mass protostars, and likely to become a diffuse moving group over hundreds of millions of years.

Contribution

This study provides detailed photometric analysis of Haffner 16 using adaptive optics, revealing its age, mass distribution, and dynamical state, highlighting its evolution into a moving group.

Findings

Haffner 16 is younger than 10 Myr.

The cluster is deficient in sub-solar mass objects compared to the solar neighborhood.

It is likely to evolve into a diffuse moving group within 100-1000 Myr.

Abstract

The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich population of PMS stars is identified, and comparisons with isochrones suggest an age < 10 Myr assuming a distance modulus of 13.5 (D = 5 kpc). When compared with the solar neighborhood, Haffner 16 is roughly a factor of two deficient in objects with sub-solar masses. PMS objects in the cluster are also more uniformly distributed on the sky than bright MS stars. It is suggested that Haffner 16 is dynamically evolved, and that it is shedding protostars with sub-solar masses. Young low mass clusters like Haffner 16 are one possible source of PMS stars in the field. The cluster will probably evolve on time scales of ~ 100 - 1000 Myr into a diffuse moving group with a mass function that is very different from that which prevailed early in its life.