2003AJ....126..918M

Adaptive optics-corrected images obtained with the Coronagraphic Imager with Adaptive Optics instrument at the 8.2 m Subaru Telescope show the presence of two subarcsecond companions to the nearby (d=19.3 pc) young star GJ 900, which was previously classified as a single member of the IC 2391 supercluster. The two companions are redder than the primary and share the same proper motion. The projected separations of B and C from the primary are 10 and 14.5 AU, respectively. The estimated masses for the two new companions depend strongly on the age of the system. For the range of ages found in the literature for IC 2391 supercluster members (from 35 to 200 Myr), the expected masses range from 0.2 to 0.4 M_☉ for the B component and from 0.09 to 0.22 M_☉ for the C component. The determination of the dynamic mass of the faintest component of GJ 900 will yield the age of the system using theoretical evolutionary tracks. The apparent separations of the GJ 900 system components meet the observational criterion for an unstable Trapezium-type system, but this could be a projection effect. Further observations are needed to establish the nature of this interesting low-mass multiple system.