Related papers: Brown Dwarfs
Over a dozen T dwarfs, brown dwarfs that exhibit methane absorption features at 1.6 and 2.2 $\micron$, have been discovered by the 2MASS survey. We discuss how the search for these objects has been made, point out some of the limitations of…
We have monitored the position of the cool Y dwarf WISEPA J182831.08+265037.8 using a combination of ground- and space-based telescopes and have determined its distance to be 11.2$_{-1.0}^{+1.3}$ pc. Its absolute H magnitude,…
Brown dwarfs bridge the gap between stars and planets, providing valuable insight into both planetary and stellar formation mechanisms. Yet the census of transiting brown dwarf companions, in particular around M dwarf stars, remains…
The 32 Orionis group is a co-moving group of roughly 20 young (24 Myr) M3-B5 stars 100 pc from the Sun. Here we report the discovery of its first substellar member, WISE J052857.69+090104.2. This source was previously reported to be an M…
Irradiated brown dwarfs (BDs) provide natural laboratories to test our understanding of substellar and irradiated atmospheres. A handful of short-period BDs around white dwarfs (WDs) have been observed, but the uniquely intense UV-dominated…
The multiplicity properties of brown dwarfs are critical empirical constraints for formation theories, while multiples themselves provide unique opportunities to test evolutionary and atmospheric models and examine empirical trends. Studies…
The spectra of brown dwarfs are key to exploring the chemistry and physics that take place in their atmospheres. Late-T dwarf spectra are particularly diagnostic due to their relatively cloud-free atmospheres and deep molecular bands. With…
Precise measurements of the fundamental properties of low-mass stars and brown dwarfs are key to understanding the physics underlying their formation and evolution. While there has been great progress over the last decade in studying the…
This chapter reviews our current knowledge of metal-poor ultracool dwarfs with spectral types later than M7. The current census of M, L, and T subdwarfs is explored. The main colour trends of subdwarfs from the optical to the mid-infrared…
Due to the nature depending on only the gravitational field, microlensing, in principle, provides an important tool to detect faint and even dark brown dwarfs. However, the number of identified brown dwarfs is limited due to the difficulty…
WD 0806-661 B is one of the coldest known brown dwarfs (T=300-345 K) based on previous mid-infrared photometry from the Spitzer Space Telescope. In addition, it is a benchmark for testing theoretical models of brown dwarfs because its age…
The census of solar neighbours is still complemented by new discoveries, mainly of very low-mass, faint dwarfs, close to or within the substellar domain. These discoveries contribute to a better understanding of the field population; its…
We review the current picture of disks around cool stars and brown dwarfs, including disk fractions, mass estimates, disk structure and dispersal, accretion, dust composition, and the debris disk phase. We discuss these in the framework of…
Brown dwarfs, which occupy a fuzzy gap in mass between stars and planets, appear to be common both in the solar neighborhood and in star-forming regions. Their origin is a topic of significant current interest and debate. Some astronomers…
We present additional analysis of the classification system presented in Allers & Liu (2013). We refer the reader to Allers & Liu (2013) for a detailed discussion of our near-IR spectral type and gravity classification system. Here, we…
We summarize and extend recent work on the theory of extrasolar giant planets (EGPs) and brown dwarfs, paying particular attention to Gliese 229 B, the albedos of EGPs, the compositions of substellar atmospheres, the connections with the…
A number of so-called ultra-cool white dwarfs have been detected in different surveys so far. However, based on anecdotal evidence it is believed that most or all of these ultra-cool white dwarfs are low-mass products of binary evolution…
Brown dwarfs and giant planets orbiting close to a host star are subjected to significant irradiation that can modify the properties of their atmospheres. In order to test the atmospheric models that are used to describe these systems, it…
We report the discovery of a population of late-M and L field dwarfs with unusual optical and near-infrared spectral features that we attribute to low gravity -- likely uncommonly young, low-mass brown dwarfs. Many of these new-found young…
We report preliminary results of a deep near-infrared search for methane-absorbing brown dwarfs; almost five years after the discovery of Gl 229b, there are only a few confirmed examples of this type of object. New J band, wide-field…