7 papers
The sub-stellar birth rate from UKIDSS
A. C. Day-Jones, F. Marocco, D. J. Pinfield +11
We present a new sample of mid L to mid T dwarfs with effective temperatures of 1100 to 1700K selected from the UKIDSS Large Area Survey and confirmed with infrared spectra from X-…
Post-common envelope binaries from SDSS - XIV. The DR7 white dwarf-main sequence binary catalogue
A. Rebassa-Mansergas, A. Nebot Gomez-Moran, M. R. Schreiber +4
We present an updated version of the spectroscopic white dwarf-main sequence (WDMS) binary catalogue from the Sloan Digital Sky Survey (SDSS). 395 new systems are serendipitous dis…
Discovery of a T dwarf + white dwarf binary system
A. C. Day-Jones, D. J. Pinfield, M. T. Ruiz +11
We present the discovery of the first T dwarf + white dwarf binary system LSPM 1459+0857AB, confirmed through common proper motion and spectroscopy. The white dwarf is a high prope…
Discovery of the first wide L dwarf + giant binary system and eight other ultra-cool dwarfs in wide binaries
Z. H. Zhang, D. J. Pinfield, A. C. Day-Jones +11
We identify 806 ultra-cool dwarfs from their SDSS riz photometry (of which 34 are newly discovered L dwarfs) and obtain proper motions through cross matching with UKIDSS and 2MASS.…
The current population of benchmark brown dwarfs
A. C. Day-Jones, D. J. Pinfield, M. T. Ruiz +7
The number of brown dwarfs (BDs) now identified tops 700. Yet our understanding of these cool objects is still lacking, and models are struggling to accurately reproduce observatio…
Rotation Velocities for M-dwarfs
J S Jenkins, L W Ramsey, H R A Jones +4
We present spectroscopic rotation velocities (v sin i) for 56 M dwarf stars using high resolution HET HRS red spectroscopy. In addition we have also determined photometric effectiv…