kosmos: Brown dwarf

Evidence: 100 • authority: 72

Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars. Their mass is approximately 13 to 80 times that of Jupiter (MJ)—not big enough to sustain nuclear fusion of hydrogen into helium in their cores, but massive enough to emit some light and heat from deuterium fusion, 2H, an isotope of hydrogen with a neutron as well as a proton, that can undergo fusion at lower temperatures. The most massive ones (> 65 MJ) can fuse lithium (7Li). Astronomers classify self-luminous objects by spectral type, a distinction intimately tied to the surface temperature -- brown dwarfs occupy types M (2100–3500 K), L (1300–2…

Evidence: 36 • authority: 72

Evidence: 30 • authority: 92

Planetary-mass exosatellite detected around the substellar companion of a star.. Brown dwarfs occupy the mass regime between planets and stars. In systems containing both a star and a substellar companion (be it a brown dwarf or an exoplanet), a third object orbiting the companion can be called an exosatellite. Exoplanet satellites can be easily described as exomoons, but it is not clear if satellites of brown dwarf companions can be called the same, as the term lacks a formal definition. Despite more than 6,000 exoplanets being discovered 1 , no exomoon has ever been confidently detected. Although there are candidates, they lack confirmation and remain controversial 2-5 . In this work, we…

Evidence: 30 • authority: 72

A sub-brown dwarf or planetary-mass brown dwarf is an astronomical object that formed in the same manner as stars and brown dwarfs (i.e. through the collapse of a gas cloud) but that has a planetary mass, therefore by definition below the limiting mass for thermonuclear fusion of deuterium (about 13 MJ). Some researchers include them in the category of rogue planets whereas others call them planetary-mass brown dwarfs.

Evidence: 25 • authority: 92

Evidence: 24 • authority: 92

Evidence: 24 • authority: 72

The Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is by far the most massive planet in the Solar System. It is approximately 2.5 times as massive as all of the other planets in the Solar System combined. Jupiter mass is a common unit of mass in astronomy that is used to indicate the masses of other similarly-sized objects, including the outer planets, extrasolar planets, and brown dwarfs, as this unit provides a convenient scale for comparison.