A possible third component in the L dwarf binary system DENIS-P J020529.0-115925 discovered with the Hubble Space Telescope

Abstract

We present results showing that the multiple system DENIS-P J020529.0-115925 is likely to be a triple system of brown dwarfs. The secondary of this previously known binary system shows a clear elongation on six images obtained at six different epochs. Significant residuals remain after PSF subtraction on these images, characteristic of multiplicity, and indicating that the secondary is probably a double itself. Dual-PSF fitting shows that the shape of the secondary is consistent with that of a binary system. These measurements show that the probability that DENIS-P J020529.0-115925 is a triple system is very high. The photometric and spectroscopic properties of the system are consistent with the presence of three components with spectral types L5, L8 and T0.

15 pages, 3 tables, 6 figures, accepted for publication in AJ. High resolution version available at ftp://ftp.mpe.mpg.de/people/hbouy/publications/denis0205.ps.gz