EDP Sciences
Free access
Volume 431, Number 2, February IV 2005
Page(s) 539 - 545
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20041459

A&A 431, 539-545 (2005)
DOI: 10.1051/0004-6361:20041459

The enigmatic brown dwarf candidate [KG2001] 102 in the Chamaeleon I cloud: Is it a multiple system?

P. Persi1, M. Tapia2, M. Gómez3, M. Roth4 and A. R. Marenzi1

1  Istituto Astrofisica Spaziale e Fisica Cosmica, CNR, via fosso del cavaliere 100, 00133 Roma, Italy
    e-mail: persi@rm.iasf.cnr.it
2  Instituto de Astronomía, UNAM, Apartado Postal 877, 22830 Ensenada, BC Mexico
3  Observatorio Astronómico de Córdoba, Laprida 854, 5000 Córdoba, Argentina
4  Las Campanas Observatory, Carnegie Institution of Washington, Casilla 601, La Serena, Chile

(Received 14 June 2004 / Accepted 11 October 2004)

We present deep $IJHK_{\rm s}$ and H 2 images of a region in the Chamaeleon I dark cloud containing the very low-mass young object [KG2001]102, in an attempt to search for multiplicity and molecular outflow in the vicinity of this object. No low-velocity shocked structures were detected in our H 2 image. The broad-band and narrow-band images show that [KG2001]102 is composed of four objects within a radius of $\sim $ $2 \arcsec$. The brightest component [KG2001]102 A shows near-IR excess emission and its mass is estimated to be in the range 33 to 55  $M_{\rm Jup}$, depending on which model is adopted. Red spectra were obtained of the two fainter components B and C. The spectrum of the former suggests a K7V spectral type while the spectrum of component C is too noisy to allow a reliable classification but rules out a late M-type. The three faint components (B, C and D) have IJHK colors that suggest a much later spectral type, with extinctions similar to other members of the cloud. The computed probability of randomly finding a pair of field stars like [KG2001]102 AB is $1.5 \times 10^{-3}$ while for a triple optical system like [KG2001]102 ABC, it would be $3.8 \times 10^{-5}$ and more than an order of magnitude lower for finding a quadruple system like this by chance projection.

Key words: stars: low-mass, brown dwarfs -- stars: formation -- infrared: stars

SIMBAD Objects

© ESO 2005