SDSS J141624.08+134826.7: A Nearby Blue L Dwarf From the Sloan Digital Sky Survey

TL;DR

This paper reports the discovery of a nearby blue L6 dwarf from SDSS data, characterized by unusual spectral features and colors, providing insights into its atmospheric properties and proximity to the Sun.

Contribution

The discovery of SDSS J141624.08+134826.7 as a nearby blue L dwarf with unique spectral features and implications for understanding cloud structures in L-type ultracool dwarfs.

Findings

Located at approximately 8.4 parsecs from the Sun.

Exhibits spectral features indicative of thin or large-grained clouds.

Likely a high-mass brown dwarf or low-mass star.

Abstract

We present the discovery of a bright (J = 13.1 mag) nearby L6 dwarf found in a search for L-type ultracool subdwarfs in the Sloan Digital Sky Survey (SDSS) Data Release 7. SDSS J141624.08+134826.7 exhibits blue near-infrared colors compared to other optically-typed L6 objects, but its optical and near-infrared spectra do not show metal-poor features characteristic of known L-type ultracool subdwarfs. Instead, SDSS J141624.08+134826.7 is probably a nearby example of the class of L dwarfs with low condensate opacities which exhibit unusually blue near-infrared colors for a given spectral type. Its deep 1.4 and 1.9 um H2O absorption bands, weak 2.3 um CO feature, strong 0.99 um FeH band, and shallow optical TiO and CaH bands resemble the spectra of other blue L dwarfs which are believed to have unusually thin or large-grained cloud structure. The luminosity of SDSS J141624.08+134826.7 implies that it is either a high-mass brown dwarf or a low mass star, depending on its age, and its UVW space motion suggests a thin-disk membership. With a spectrophotometric distance of 8.4 +/- 1.9 pc, SDSS J141624.08+134826.7 is one of the nearest L dwarfs to the Sun and is therefore an excellent target for high resolution imaging, spectroscopic, and astrometric follow-up observations.