Search
Now showing items 31-40 of 87
Measuring ultracool properties from the UKIDSS Large Area Survey
(EDP Sciences, 2013)
We discuss the properties and of ultracool and brown dwarfs that can be measured from current large area surveys and how fundamental parameters, such as the mass function and formation history can be measured, describing ...
Purple dwarfs : New L subdwarfs from UKIDSS and SDSS
(EDP Sciences, 2013)
The first L subdwarf was a discovered only ten years ago. Less than ten L subdwarfs been published in the literature to date. Metal-poor ultracool atmospheres has not been well understood. Halo mass function cross substellar ...
Identifying ultra-cool dwarfs at low Galactic latitudes : a southern candidate catalogue
(2012-12)
We present an ultra-cool dwarf (UCD) catalogue compiled from low southern Galactic latitudes and mid-plane, from a cross-correlation of the Two Micron All-Sky Survey (2MASS) and the SuperCOSMOS survey. The catalogue contains ...
J-band variability of M dwarfs in the WFCAM Transit Survey
(2012-12)
We present an analysis of the photometric variability of M dwarfs in the Wide Field Camera (WFCAM) Transit Survey. Although periodic light-curve variability in low mass stars is generally dominated by photospheric star ...
The brightest pure-H ultracool white dwarf
(2012-10)
We report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo ...
Red Optical Planet Survey: : a new search for habitable earths in the southern sky
(2012-07-01)
We present the first results from our Red Optical Planet Survey (ROPS) to search for low mass planets orbiting late type dwarfs (M5.5V - M9V) in their habitable zones (HZ). Our observations, with the red arm MIKE spectrograph ...
Physical parameters of the binary star CM draconis components
(2012-05)
Spectra of the eclipsing binary star CM Dra consisting of two M dwarfs are discussed in detail. High-resolution echelle spectra (R = 47000) obtained using the 4.2 m William Hershel telescope are used. The temperatures and ...
Values of v sin i-s for late-type stars from spectral synthesis in the K-band region.
(2012-05)
We analyse medium-resolution spectra (R similar to 18 000) of 19 late type dwarfs in order to determine v sin i values using synthetic rather than observational template spectra. For this purpose, observational data around ...
The Properties of the 500 K Dwarf UGPS J072227.51-054031.2, and a Study of the Far-Red Flux of Cold Brown Dwarfs
(2012-04-01)
We present i and z photometry for 25 T dwarfs and one L dwarf. Combined with published photometry, the data show that the i - z, z - Y and z - J colors of T dwarfs are very red, and continue to increase through to the ...
Benchmark cool companions : Ages and abundances for the PZ Tel system
(2012-03)
We present new ages and abundance measurements for the pre-main sequence star PZ Tel. PZ Tel was recently found to host a young and low-mass companion. Using FEROS spectra we have measured atomic abundances (e.g. Fe and ...