The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog

TL;DR

This paper reports the discovery of a young, low-mass planetary analog in the TW Hydrae association, confirmed through spectral analysis and kinematic measurements, and estimates its mass to be comparable to giant planets.

Contribution

It identifies the nearest isolated member of TW Hydrae with a mass similar to giant planets, using spectral and kinematic data to confirm its membership and properties.

Findings

Confirmed youth of the object through spectral analysis.

Estimated mass of 4.3--7.6 Jupiter masses.

Identified as the nearest isolated TW Hydrae member.

Abstract

In a recent search for unusually red L and T dwarfs, we identified 2MASS J11193254-1137466 as a likely young L7 dwarf and potential member of the TW Hydrae association. We present spectra that confirm the youth of this object. We also measure a radial velocity of 8.5 +/- 3.3 km/s that, together with the sky position, proper motion and photometric distance, results in a 92% probability of membership in the TW Hydrae association, with a calibrated field contamination probability of 0.0005% using the BANYAN II tool. Using the age of TW Hydrae and the luminosity of 2MASS J11193254-1137466, we estimate its mass to be 4.3--7.6 MJup. It is the lowest-mass and nearest isolated member of TW Hydrae at a kinematic distance of 28.9 +/- 3.6 pc, and the second-brightest isolated <10 MJup object discovered to date.