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 identify the L dwarf 2MASS J20261584-2943124 as an unresolved spectralbinary, based on low-resolution, near-infrared spectroscopy from IRTF/SpeX. Thedata reveal a peculiar absorption feature at 1.6 microns, previously noted inthe spectra of other very low-mass spectral binaries, which likely arises fromoverlapping FeH and CH4 absorption bands in the blended light of an L dwarf/Tdwarf pair. Spectral template matching analysis indicates component types ofL0.5 and T6, with relative brightness Delta H = 4.2+/-0.6. Laser guide staradaptive optics imaging observations with Keck/NIRC2 fail to resolve thesource, indicating a maximum separation at the observing epoch of 0.25 arcsec,or a projected separation of 9 AU assuming a distance of 36+/-5 pc. With an agethat is likely to be relatively older (>5 Gyr based on the system's large vtanand mass ratio arguments, the relative motion of the potentially "massive"(0.06-0.08 Msun) components of 2MASS J2026-2943 may be detectable throughradial velocity variations, like its earlier-type counterpart 2MASSJ03202839-0446358 (M8+T5), providing dynamical mass measurements that span thehydrogen burning limit.

2MASS J20261584-2943124: An Unresolved L0.5 + T6 Spectral Binary