English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We confirm the substellar nature of ULAS J141623.94+134836.3, a common propermotion companion to the blue L dwarf SDSS J141624.08+134826.7 identified byBurningham et al. and Scholz. Low-resolution 0.8-2.4 micron spectroscopyobtained with IRTF/SpeX shows strong H2O and CH4 absorption bands, consistentwith a T7.5 spectral type, and we see possible indications of NH3 absorption inthe 1.0-1.3 micron region. More importantly, the spectrum of ULAS J1416+1348shows a broadened Y-band peak and highly suppressed K-band flux, bothindicative of high surface gravity and/or subsolar metallicity. These traitsare verified through spectral model fits, from which we derive atmosphericparameters Teff = 650+/-60 K, log g = 5.2+/-0.4 cgs, [M/H] <= -0.3 and Kzz =10^4 cm^2/s, the temperature being significantly warmer than that estimated byBurningham et al. These fits also indicate a model-dependent spectroscopicdistance of 10.6(+3.0,-2.8) pc for ULAS J1416+1348, formally consistent withthe 7.9+/-1.7 pc astrometric distance for SDSS J1416+1348 from Scholz. Thecommon peculiarities of these two co-spatial, co-moving sources suggest thattheir unusual blue colors - and those of other blue L and T dwarfs in general -arise from age or metallicity, rather than cloud properties alone.

ULAS J141623.94+134836.3: a Blue T Dwarf Companion to a Blue L Dwarf