A lightcurve for the most famous young brown dwarf
The object ISO-Oph 102 (or 2MASS J16270659-2441488) is one of the most prominent young brown dwarfs that we know of: It was one of the first brown dwarfs found to have a disk (Natta et al. 2002), it was one of the first brown dwarfs known to be actively accreting from the disk (Natta et al. 2004), and it was the first with a resolved outflow (Whelan et al. 2005). The outflow is still the only one (for BDs) seen in the molecular gas (Phan Bao et al. 2008). The object is one of the classic examples for a 'T Tauri like' (i.e. star-like) early evolution of brown dwarfs, possibly indicating a star-like origin.
Here we test whether ISO-Oph 102 shows evidence for the typical 'T Tauri' variability seen in many young stars, which is usually caused by a combination of accretion, magnetic activity, and obscurations by the disk. The figure shows five multi-wavelength photometry datapoints spanning four months, obtained with Andicam at the 1.3m telescope at CTIO as part of the SMARTS collaboration. Apart from the first datapoint, which could be affected by some transient event, there is no evidence for any variability. In addition, the older, published near-infrared magnitudes from 1999 and 2005-6 (from 2MASS, UKIDSS and Alves de Oliveira & Casali 2008) are only marginally fainter than the magnitudes measured this year (by 0.2 mag in J, 0.1 mag in K). This null result indicates a remarkable stability in the activity level and the accretion flow in this object over more than 10 years.