Related papers: Retrieval Study of Brown Dwarfs Across the L-T Seq…

Young planetary-mass objects and brown dwarfs near the L/T spectral transition exhibit enhanced spectrophotometric variability over field brown dwarfs. Patchy clouds, auroral processes, stratospheric hot spots, and complex carbon chemistry…

We report an attempt to interpret the spectra of L and T dwarfs with the use of the Unified Cloudy Model (UCM). For this purpose, we extend the grid of the UCMs to the cases of log g = 4.5 and 5.5. The dust column density relative to the…

We present a 0.6-4.1 micron spectroscopic sequence of M, L, and T dwarfs. The spectra have R~2000 from 0.9 to 2.4 microns and R=2500-200 from 2.9 to 4.1 microns. These new data nearly double the number of L and T dwarfs that have reported…

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 the common proper motion inferred from…

A search for young substellar objects in the rho Oph cloud core region has been made using the deep-integration Combined Calibration Scan images of the 2MASS extended mission in J, H and Ks bands, and Spitzer IRAC images at 3.6, 4.5, 5.8…

We present new evolution sequences for very low mass stars, brown dwarfs and giant planets and use them to explore a variety of influences on the evolution of these objects. We compare our results with previous work and discuss the causes…

We present multiple-epoch photometric monitoring in the $J$, $H$, and $K_s$ bands of the T1.5 dwarf 2MASS J21392676+0220226 (2M2139), revealing persistent, periodic ($P=7.721\pm$0.005 hr) variability with a peak-to-peak amplitude as high as…

We present a technique to identify spectrophotometrically variable L7-T3 brown dwarfs with single-epoch, low-resolution, near-infrared SpeX spectra. We calculated spectral indices on known variable brown dwarfs and used them to select 11…

Condensate clouds fundamentally impact the atmospheric structure and spectra of exoplanets and brown dwarfs but the connections between surface gravity, cloud structure, dust in the upper atmosphere, and the red colors of some brown dwarfs…

We present an analysis of low resolution infrared spectra for 20 brown dwarf candidates in the core of the $\rho$ Ophiuchi molecular cloud. Fifteen of the sources display absorption-line spectra characteristic of late-type stars. By…

L dwarfs exhibit low-level, rotationally-modulated photometric variability generally associated with heterogeneous, cloud-covered atmospheres. The spectral character of these variations yields insight into the particle sizes and vertical…

Most brown dwarfs have atmospheres with temperatures cold enough to form clouds. A variety of materials likely condense, including refractory metal oxides and silicates; the precise compositions and crystal structures of predicted cloud…

We present analyses of high resolution and medium resolution spectra of early L dwarfs. We used our latest set of model atmospheres to reproduce and analyze the observed features. We can model the optical flux and the atomic line profiles…

Lithium is an important element for the understanding of ultracool dwarfs because it is lost to fusion at masses above $\sim 68\, M_{\rm J}$. Hence, the presence or absence of atomic Li has served as an indicator of the nearby H-burning…

We examine the hypothesis that the red near-infrared colors of some L dwarfs could be explained by a "dust haze" of small particles in their upper atmospheres. This dust haze would exist in conjunction with the clouds found in dwarfs with…

Optical and near-infrared spectroscopy of the newly discovered peculiar L dwarf 2MASS J11263991-5003550 are presented. Folkes et al. identified this source as a high proper motion L9+/-1 dwarf based on its strong H2O absorption at 1.4…

We present a uniform forward-modeling analysis of 90 late-M and L dwarfs in nearby young (~$10-200$ Myr) moving groups, the Pleiades, and the Hyades using low-resolution ($R\approx150$) near-infrared ($0.9-2.4$ $\mathrm{\mu m}$) spectra and…

The determination of the brown dwarf binary fraction may contribute to the understanding of the substellar formation mechanisms. Unresolved brown dwarf binaries may be revealed through their peculiar spectra or the discrepancy between…

We report the detection of more than 48 velocity-resolved ground rotational state transitions of H2(16)O, H2(18)O, and H2(17)O - most for the first time - in both emission and absorption toward Orion KL using Herschel/HIFI. We show that a…

We present a kinematic analysis of 152 low surface gravity M7-L8 dwarfs by adding 8 parallaxes, 38 radial velocities, and 19 proper motions. We find 39 objects to be high-likelihood or bona fide members of nearby moving groups, 92 objects…