A star with less than a tenth the mass of the sun that isn't hot enough to transform hydrogen into helium Chandresekhar limit - About one and a half times the mass of the sun. Exclusion principle repulsion among the electrons in a star more massive than this can't support the star against its own gravity
A dud star, a compact mass of hydrogen which lacked the gravity to start fusing large quantities of hydrogen into helium.
An object substantially (~13 x) larger than Jupiter but with a mass no more than 40 percent that of the Sun. These objects are not big enough for gravitational collapse to heat them to the point that nuclear reactions can be triggered. Brown dwarfs may be very common in the universe and could even have planets in a habitable zone.
A brown dwarf is a failed star. The forces of pressure and gravity reached a stalemate before the temperature in the star's core became hot enough to ignite nuclear reactions in the core, which is what happens in all other stars to make them hot and bright.
An object intermediate in size between a planet and a star. The approximate mass range is from about 1/100 of the mass of the Sun up to the lower mass limit for self-sustaining nuclear reactions, which is 0.072 the mass of the Sun.
A celestial body that resembles a star but does not emit light because it is too small to ignite internal nuclear fusion. Brown dwarfs are extremely difficult to detect and their existence was only recently confirmed.
An electron-degenerate star which is so cool that it gives off very little visible light, but is still detectable through its infrared radiation. A star which, as it contracted, became electron-degenerate, and unable to contract or heat up any further, before becoming hot enough to undergo thermonuclear fusion.
a cool or "failed" star, which lacks the mass to ignite and shine like our Sun
a little smaller than a star, a lot bigger than a planet, and only hypothetical--until now
a little understood intermediate class of celestial object that is too small to sustain hydrogen fusion reactions, like those that power our Sun
an intermediate stage in becoming a star--the next stage in Jupiter's evolution
an object formed by the same processes that produce a star, but is not massive enough to burn hydrogen
an object that formed the way stars do, from the collapse of a molecular cloud , but that, because it is not massive enough, does not sustain stable hydrogen fusion in its core
an object that is something bigger than a planet, but smaller than a star
an object that is somewhere in the netherworld between stars and planets
an object that started to collapse to become a star but was not massive enough to be able to initiate nuclear reactions
an object too massive and hot to be classified as a planet, but too small and cool to burn like a star
a self-gravitating gaseous object composed mainly of hydrogen and helium, whose mass is too small to induce stable hydrogen fusion in its interior
a star that failed to gather enough mass to ignite
a very small star, so small that it can't produce energy through nuclear reactions the way the normal stars do
a starlike object that does not radiate energy because it has insufficient mass for nuclear fusion.
A star with insufficient mass to initiate a fusion reaction
a celestial body that is too small to reach the temperatures that are necessary in the centre to trigger the reactions of nuclear fusion, and to become a star. Cerenkov Light a luminous emission that happens when a charged particle, such as a particle of the cosmic rays, crosses a material medium at a speed higher than that of light in the same medium. It can find an application in some kinds of particle counters.
A failed star. Brown dwarfs are thought to form in the same manner as stars, however their mass is less than 0.08 times that of the Sun and, therefore, brown dwarfs are not able to sustain a core hydrogen burning fusion reaction.
A low-luminosty object with a mass that is intermediate between that of a star and a giant planet. With a mass of about 1-8% of the Sun, a brown dwarf is too small to ignite the thermonuclear fusion that defines a star. A theoretical entity until 1995, hundreds of these cool objects have been discovered in recent years.
A star that never became massive enough to start core hydrogen burning.
A body of very dense clouds and dust resembling a planet.
Remnant of a fragment of collapsing gas and dust that did not contain enough mass to initiate core nuclear fusion. Such objects are frozen somewhere along their pre-main-sequence contraction phase, continually cooling into compact dark objects. Because of their small sizes and low temperatures they are extremely difficult to detect observationally.
A very cool, low luminosity star whose mass is not sufficient to ignite nuclear fusion.
A brown dwarf is a "star" whose mass is too small to have nuclear fusion occur at its core (the temperature and pressure at its core are insufficient for fusion) - a failed star. A brown dwarf is not very luminous. It is usually regarded as having a mass between 10 28 kg and 84 x 10 28 kg. It continues to cool down and contract, turning into a compact dark object that is not easily detected.
Either a supermassive planet or a failed star, a brown dwarf has insufficient mass to sustain nuclear fusion.
A "failed" star, larger than a planet but smaller than a star, that is not massive enough to ignite a nuclear fusion reaction at its core.
a celestial body that is too small to reach the temperatures that are necessary in the centre to trigger the reactions of nuclear fusion, and to become a star. Celestial Equator imaginary plane marked on the celestial sphere by the extension of the terrestrial equatorial plane
Brown dwarfs are sub-stellar objects with a mass below that necessary to maintain hydrogen-burning nuclear fusion reactions in their cores, as do stars on the main sequence, but which have fully convective surfaces and interiors, with no chemical differentiation by depth. Brown dwarfs occupy the mass range between that of large gas-giant planets and the lowest mass stars (anywhere between 75 and 80 Jupiter masses). Currently there is a large ambiguity as to what separates a brown dwarf from a giant planet at very low brown dwarf masses (~13 Jupiter masses).