Letter to the Editor

The first brown dwarf with a disk in Chamaeleon II

¹ INAF - Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy e-mail: jmae@na.astro.it
² Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia, 78, 95123 Catania, Italy
³ INAF - Osservatorio Astrofisico di Catania, via S. Sofia, 78, 95123 Catania, Italy
⁴ Center for Astrophysics, Harvard
⁵ Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands
⁶ INAF – IASF Roma, via fosso del cavaliere, 100, 00133 Roma, Italy

Received: 27 March 2006
Accepted: 20 April 2006

Abstract

In this letter we characterize the candidates for young stars and brown dwarfs detected in a survey with ISOCAM in the Chamaeleon II dark cloud. Photometric data coming from a wide-field optical imaging survey, combined with IR measurements from the 2MASS catalogue and from the Spitzer satellite, allow us to study the nature of the candidates. Using intermediate-band filters we can provide a first estimate of the temperatures for objects cooler than about 3800 K. On the basis of spectroscopic and photometric data, we confirm that ISO-CHA II 13 is a young substellar object with a mass of about . It is thus the first object in Cha II whose substellar nature has been spectroscopically confirmed. By having a temperature of about 2880 K and displaying a substantial infrared excess, it joins the list of young brown dwarfs observed to have a surrounding disk.