Parallaxes of Southern Extremely Cool objects

We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multiepoch photometry of L and early T dwarfs. The observations were made on 108 nights over the course of 8yr using the Wide Field Imager on the ESO 2.2m telescope. We present 118 new parallaxes of L and T dwarfs of which 52 have no published values and 24 of the 66 published values are preliminary estimates from this program. The parallax precision varies from 1.0 to 15.5mas with a median of 3.8mas. We find evidence for two objects with long term photometric variation and 24 new moving group candidates. We cross-match our sample to published photometric catalogues and find standard magnitudes in up to 16 pass-bands from which we build spectral energy distributions and H-R diagrams. This allows us to confirm the theoretically anticipated minimum in radius between stars and brown dwarfs across the hydrogen burning minimum mass. We find the minimum occurs between L2 and L6 and verify the predicted steep dependence of radius in the hydrogen burning regime and the gentle rise into the degenerate brown dwarf regime. We find a relatively young age of ~2Gyr from the kinematics of our sample.

Cone search capability for table J/MNRAS/481/3548/table2 (Astrometric parameters of PARSEC targets)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/481/3548
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/481/3548
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/481/3548
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/481/3548
Provenance
Creator Smart R.L.; Bucciarelli B.; Jones H.R.A.; Marocco F.; Andrei A.H.,Goldman B.; Mendez R.A.; d'Avila V.A.; Burningham B.; Camargo J.I.B.,Crosta M.T.; Dapra M.; Jenkins J.S.; Lachaume R.; Lattanzi M.G.,Penna J.L.; Pinfield D.J.; da Silva Neto D.N.; Sozzetti A.; Vecchiato A.
Publisher CDS
Publication Year 2022
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy