Stephens, D. C., Leggett, S. K., Cushing, Michael C., Marley, Mark S., Saumon, D., Geballe, T. R., ...
We present new 5.2-14.5 micron low-resolution spectra of 14 mid-L to mid-T dwarfs, as well as 3.0-4.1 micron spectra for five of these dwarfs. These data are supplemented by existing red and...
The Physical Properties of Four ~600 K T Dwarfs (2009)
Leggett, S. K., Cushing, Michael C., Saumon, D., Marley, M. S., Roellig, T. L., Warren, S. J., ...
We present Spitzer 7.6-14.5 μm spectra of ULAS J003402.77–005206.7 and ULAS J133553.45+113005.2, two T9 dwarfs with the latest spectral types currently known. We fit synthetic spectra and...
A Photometric Analysis of ZZ Ceti Stars: A Parameter-Free Temperature Indicator? (2009)
Bergeron, P., Leggett, S. K., Harris, H. C.
We present a model atmosphere analysis of optical VRI and infrared JHK photometric data of about two dozen ZZ Ceti stars. We first show from a theoretical point of view that the resulting energy...
The discovery of an M4+T8.5 binary system (2009)
Burningham, Ben, Pinfield, D. J., Leggett, S. K., Tinney, C. G., Liu, M. C., Homeier, D., ...
We report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. At a distance of 12.50 (+0.75,-0.67) pc, the angular separation of 32arcsec corresponds to a projected...
The Physical Properties of Four ~600K T Dwarfs (2009)
Leggett, S. K., Cushing, M. C., Saumon, D., Marley, M. S., Roellig, T. L., Warren, S. J., ...
We present Spitzer 7.6-14.5um spectra of ULAS J003402.77-005206.7 and ULAS J133553.45+113005.2, two T9 dwarfs with the latest spectral types currently known. We fit synthetic spectra and photometry...
Spectroscopic Detection of Carbon Monoxide in Two Late-type T Dwarfs (2009)
Geballe, T. R., Saumon, D., Golimowski, D. A., Leggett, S. K., Marley, M. S., Noll, K. S.
M band spectra of two late-type T dwarfs, 2MASS J09373487+2931409, and Gliese 570D, confirm evidence from photometry that photospheric CO is present at abundance levels far in excess of those...
Cool White Dwarfs Identified in the Second Data Release of the UKIRT Infrared Deep Sky Survey (2008)
Lodieu, N., Leggett, S. K., Bergeron, P., Nitta, A.
We have paired the Second Data Release of the Large Area Survey of the UKIRT Infrared Deep Sky Survey with the Fifth Data Release of the Sloan Digital Sky Survey to identify ten cool white dwarf...
Moderate-resolution Spitzer infrared spectrograph observations of M, L, and T dwarfs (2008)
Mainzer, A. K., Roellig, Thomas L., Saumon, D., Marley, Mark S., Cushing, Michael C., Sloan, G. C., ...
We present 10-19 μm moderate-resolution spectra of 10 M dwarfs, one L dwarf, and two T dwarf systems obtained with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. The IRS...
HN Peg B: A Test of Models of the L to T Dwarf Transition (2008)
Leggett, S. K., Saumon, D., Albert, Loic, Cushing, Michael C., Liu, Michael C., Luhman, K. L., ...
Luhman and collaborators recently discovered an early-T dwarf companion to the G0 dwarf star HN Peg, using Spitzer Infrared Array Camera (IRAC) images. Companionship was established on the basis of...
CLOUDS search for variability in brown dwarf atmospheres (2008)
Goldman, B., Cushing, M. C., Marley, M. S., Artigau, É., Baliyan, K. S., Béjar, V. J. S., ...
Context. L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into...
Exploring the substellar temperature regime down to ~550K (2008)
Burningham, Ben, Pinfield, D. J., Leggett, S. K., Tamura, M., Lucas, P. W., Homeier, D., ...
We report the discovery of three very late T dwarfs in the UKIRT Infrared Deep Sky Survey (UKIDSS) Third Data Release: ULAS J101721.40+011817.9 (ULAS1017), ULAS J123828.51+095351.3 (ULAS1238) and...
Goldman, B., Cushing, M. C., Marley, M. S., Artigau, É, Baliyan, K. S., Béjar, V. J. S., ...
Context: L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into...
Michael A. Strauss, Xiaohui Fan, James E. Gunn, S. K. Leggett, T. R. Geballe, Jeffrey R. Pier, ...
We report the discovery of the coolest field dwarf yet known, selected as an unresolved object with extremely red colors from commissioning imaging data of the Sloan Digital Sky Survey. Its spectrum...
A very cool brown dwarf in UKIDSS DR1 (2007)
Warren, S. J., Mortlock, D. J., Leggett, S. K., Pinfield, D. J., Homeier, D., Dye, S., ...
(abridged) We report the discovery of a very cool brown dwarf, ULAS J003402.77-005206.7 (ULAS J0034-00), identified in UKIDSS DR1. We provide optical, near-infrared, and mid-infrared photometry of...
Trigonometric Parallaxes of Central Stars of Planetary Nebulae (2006)
Harris, Hugh C., Dahn, Conard C., Canzian, Blaise, Guetter, Harry H., Leggett, S. K., Levine, Stephen E., ...
Trigonometric parallaxes of 16 nearby planetary nebulae are presented, including reduced errors for seven objects with previous initial results and results for six new objects. The median error in...
Physical parameters of two very cool T dwarfs (2006)
Saumon, D., Marley, M. S., Leggett, S. K., Geballe, T. R., Stephens, D., Golimowski, D. A., ...
We present new infrared spectra of the T8 brown dwarf 2MASS J04151954-0935066: 2.9-4.1 micron spectra obtained with the Infrared Camera and Spectrograph on the Subaru Telescope, and 5.2-14.5 micron...
The UKIRT infrared deep sky survey early data release (2006)
Dye, S., Warren, S.J., Hambly, N.C., Cross, N.J.G., Hodgkin, S.T., Irwin, M.J., ...
This paper defines the UKIRT Infrared Deep Sky Survey (UKIDSS) Early Data Release (EDR). UKIDSS is a set of five large near-infrared surveys being undertaken with the United Kingdom Infrared...
The UKIRT Infrared Deep Sky Survey First Data Release (2006)
Warren, S. J., Hambly, N. C., Dye, S., Almaini, O., Cross, N. J. G., Edge, A. C., ...
The First Data Release (DR1) of the UKIRT Infrared Deep Sky Survey (UKIDSS) took place on 2006 July 21. UKIDSS is a set of five large near-infrared surveys, covering a complementary range of areas,...
Leggett, S. K., Saumon, D., Marley, M. S., Geballe, T. R., Golimowski, D. A., Stephens, D., ...
We present new L' (3.75 um) photometry of six L and T dwarfs, and M' (4.70 um) photometry of ten L and T dwarfs, observed at Gemini Observatory, and new 3.55, 4.49, 5.73 and 7.87 um photometry of...
JHK Observations of Faint Standard Stars in the Mauna Kea Near-Infrared Photometric System (2006)
Leggett, S. K., Currie, M. J., Varricatt, W. P., Hawarden, T. G., Adamson, A. J., Buckle, J., ...
JHK photometry in the Mauna Kea Observatory (MKO) near-IR system is presented for 115 stars. Of these, 79 are UKIRT standards and 42 are LCO standards. The average brightness is 11.5 mag, with a...
Ammonia as a tracer of chemical equilibrium in the T7.5 dwarf Gliese 570D (2006)
Saumon, D., Marley, M. S., Cushing, M. C., Leggett, S. K., Roellig, T. L., Lodders, K., ...
We present the first analysis of an optical to mid-infrared spectrum of the T7.5 dwarf Gliese 570D with model atmospheres, synthetic spectra, and brown dwarf evolution sequences. We obtain precise...
Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey (2006)
Chiu, K., Fan, X., Leggett, S. K., Golimowski, D. A., Zheng, W., Geballe, T. R., ...
We present near-infrared observations of 71 newly discovered L and T dwarfs, selected from imaging data of the Sloan Digital Sky Survey (SDSS) using the i-dropout technique. Sixty-five of these...
Spitzer Infrared Spectrograph Observations of M, L, and T Dwarfs (2004)
Roellig, T. L., Van Cleve, J. E., Sloan, G. C., Wilson, J. C., Saumon, D., Leggett, S. K., ...
We present the first mid-infrared spectra of brown dwarfs, together with observations of a low-mass star. Our targets are the M3.5 dwarf GJ 1001A, the L8 dwarf DENIS-P J0255-4700, and the T1/T6...
Knapp, G. R., Leggett, S. K., Fan, X., Marley, M. S., Geballe, T. R., Golimowski, D. A.
We present JHK photometry and spectroscopy for a sample of newly identified L and T dwarfs from the Sloan Digital Sky Survey (SDSS) and known dwarfs from the SDSS and the Two Micron All Sky Survey...
L' and M' Photometry of Ultracool Dwarfs (2004)
Golimowski, D. A., Leggett, S. K., Marley, M. S., Fan, X., Geballe, T. R., Knapp, G. R., ...
We have compiled L' and M' photometry of 63 single and binary M, L,and T dwarfs obtained at UKIRT using the MKO filter set. This compilation includes new L' data for 8 L dwarfs and 13 T dwarfs and...
Vrba, F. J., Henden, A. A., Luginbuhl, C. B., Guetter, H. H., Munn, J. A., Canzian, B., ...
We present preliminary trigonometric parallaxes and proper motions for 22 L dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager. Relative to absolute parallax corrections are made by...
Model Atmosphere Analysis of Two Very Cool White Dwarfs (2002)
A detailed analysis of the very cool white dwarfs SDSS 1337+00 and LHS 3250 is presented. Model atmosphere calculations with improved collision-induced absorptions by molecular hydrogen indicate that...
Geballe, T. R., Knapp, G. R., Leggett, S. K., Fan, X., Golimowski, D. A.
We present 0.6-2.5um, R~400 spectra of twenty-seven cool, low luminosity stars and substellar objects. Based on these and previously published spectra we develop a preliminary spectral classification...