SSPMJ1102-3431 brown dwarf characterization from accurate proper motion and trigonometric parallax

TL;DR

This study accurately measures the proper motion and parallax of the young brown dwarf SSSPMJ1102-3431 to confirm its membership in the TW Hydrae Association and explore its potential binary relationship with TW Hya.

Contribution

The paper provides precise trigonometric parallax and proper motion measurements of SSSPMJ1102-3431, confirming its TWA membership and assessing its binary status with TW Hya.

Findings

Confirmed TWA membership of SSSPMJ1102-3431

Measured physical parameters of the brown dwarf

Supported the binary companion hypothesis

Abstract

In 2005, Scholz and collaborators (Scholz et al. 2005) discovered, in a proper motion survey, a young brown dwarf SSSPMJ1102-3431(SSSPMJ1102) of spectral type M8.5, probable member of the TW Hydrae Association (TWA) and possible companion of the T Tauri star TW Hya. The physical characterization of SSSPMJ1102 was based on the hypothesis that it forms a binary system with TW Hya. The recent discovery of a probable giant planet inside the TW Hya protoplanetary disk with a very short-period (Setiawan et al. 2008) and a disk around SSSPMJ1102 (Riaz and Gizis 2008) make it especially interesting and important to measure well the physical parameters of SSSPMJ1102. Trigonometric parallax and proper motion measurements of SSSPMJ1102 are necessary to test for TWA membership and, thus, to determine the mass and age of this young brown dwarf and the possibility that it forms a wide binary system with TW Hya. Two years of regular observations at the ESO NTT/SUSI2 telescope, have enabled us to determine the trigonometric parallax and proper motion of SSSPMJ1102. Our parallax and proper motion determination allow us to precisely describe the physical properties of this low mass object and to confirm its TWA membership. Our results are not incompatible with the hypothesis that SSSPMJ1102 is a binary companion of the star TW Hya.