Cosma Home > Communication > Knowledge > Realm > Physical > Universe > Planetary System > Brown Dwarf

Spotlight

Pages

Physical Realm
Universe Astronomical Instrument
Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon

Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Trans-Neptunian Object
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid

Resources

These are organized by a classification scheme developed exclusively for Cosma. More…

General

Encyclopedia

Brown dwarf is a substellar object that occupies the mass range between the heaviest gas giant planets and the lightest stars, having masses between approximately 13 to 75–80 times that of Jupiter (MJ), or approximately 2.5×1028 kg to about 1.5×1029 kg. Below this range are the sub-brown dwarfs, and above it are the lightest red dwarfs (M9 V). Brown dwarfs may be fully convective, with no layers or chemical differentiation by depth.

Unlike the stars in the main sequence, brown dwarfs are not massive enough to sustain nuclear fusion of ordinary hydrogen (1H) to helium in their cores. They are, however, thought to fuse deuterium (2H) and to fuse lithium (7Li) if their mass is above a debated threshold of 13 MJ and 65 MJ, respectively. It is also debated whether brown dwarfs would be better defined by their formation processes rather than by their supposed nuclear fusion reactions.

Stars are categorized by spectral class, with brown dwarfs designated as types M, L, T, and Y.[ Despite their name, brown dwarfs are of different colors. Many brown dwarfs would likely appear magenta to the human eye, or possibly orange/red. Brown dwarfs are not very luminous at visible wavelengths.

There are planets known to orbit brown dwarfs: 2M1207b, MOA-2007-BLG-192Lb, and 2MASS J044144b.

At a distance of about 6.5 light years, the nearest known brown dwarf is Luhman 16, a binary system of brown dwarfs discovered in 2013. HR 2562 b is listed as the most-massive known exoplanet (as of December 2017) in NASA’s exoplanet archive, despite having a mass (30±15 MJ) more than twice the 13-Jupiter-mass cutoff between planets and brown dwarfs. — Wikipedia

Encyclopædia Britannica

Introduction

Search

WolframAlpha

Education

Government

Document

USA.gov

More…

Phys.org - latest science and technology news stories Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.

A crystal ball into our solar system's future
on October 13, 2021 at 4:55 pm
Astronomers have discovered the very first confirmed planetary system that resembles the expected fate of our solar system, when the Sun reaches the end of its life in about five billion years.
Astronomers see dust disk around young...
on October 13, 2021 at 1:50 pm
An international team of astronomers led by scientists from Leiden University has for the first time characterized a dust disk surrounding a young super-Jupiter, which is either a giant planet or brown dwarf. They used so-called direct imaging observations at mid-infrared wavelengths. They detected emission from the disk and speculate that moons may have formed. The researchers will publish their findings in The Astronomical Journal.
What happens to interstellar objects captured by...
on September 28, 2021 at 12:55 pm
Now that we know that interstellar objects (ISOs) visit our solar system, scientists are keen to understand them better. How could they be captured? If they're captured, what happens to them? How many of them might be in our solar system?
Scientists discover the molecular mechanism of...
on September 6, 2021 at 3:58 pm
Rice viruses are prevalent in many rice-growing countries and often cause serious damages to rice production. Among them, the rice black-streaked dwarf virus (RBSDV), transmitted by the small brown planthopper Laodelphax striatellus, causes tremendous losses in China's grain yields every year. Therefore, discovering the transmission mechanism of RBSDV is of immense significance for its effective control.
An accidental discovery hints at a hidden...
on August 31, 2021 at 7:20 pm
Brown dwarfs aren't quite stars and aren't quite planets, and a new study suggests there might be more of them lurking in our galaxy than scientists previously thought.