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 present near-infrared spectroscopy for 52 ultracool dwarfs, including twonewly discovered late-M dwarfs, one new late-M subdwarf candidate, three new Land four new T dwarfs. We also present parallaxes and proper motions for 21 ofthem. Four of the targets presented here have previous parallax measurements,while all the others are new values. This allow us to populate further thespectral sequence at early types (L0-L4). Combining the astrometric parameterswith the new near-infrared spectroscopy presented here, we are able toinvestigate further the nature of some of the objects. In particular, we findthat the peculiar blue L1 dwarf SDSS J133148.92-011651.4 is a metal-poorobject, likely a member of the galactic thick disk. We discover a new Msubdwarf candidate, 2MASS J20115649-6201127. We confirm the low-gravity natureof EROS-MP J0032-4405, DENIS-P J035726.9-441730, and 2MASS J22134491-2136079.We present two new metal-poor dwarfs: the L4pec 2MASS J19285196-4356256 and theM7pec SIPS2346-5928. We also determine the effective temperature and bolometricluminosity of the 21 targets with astrometric measurements, and we obtain a newpolynomial relation between effective temperature and near-infrared spectraltype. The new fit suggests a flattening of the sequence at the transitionbetween M and L spectral types. This could be an effect of dust formation, thatcauses a more rapid evolution of the spectral features as a function of theeffective temperature.

Parallaxes of Southern Extremely Cool objects (PARSEC) II: Spectroscopic Follow-up and Parallaxes of 52 Targets