The coolest brown dwarf so far discovered has a temperature as low as 500 -> 600 Kelvin and have a spectral class of T9
Brown dwarfs are substellar objects that are larger and more massive than planets like Jupiter. They are not massive enough to sustain nuclear fusion in their cores, which is a defining characteristic of stars. Jupiter, on the other hand, is a gas giant planet in our solar system.
White dwarfs.
No. Red giants have temperatures comparable to those of red dwarfs. Even cooler are brown dwarfs, which are objects that are in the intermediate range between planets and stars.
A star with the lowest temperature would appear red in color. These stars are known as red dwarfs and are cooler compared to other types of stars like yellow dwarfs (like our sun) or blue giants.
A brown dwarf is a substellar object that is larger than a planet but too small to sustain nuclear fusion in its core to become a star. They are often referred to as "failed stars" because they lack the mass and temperature needed for hydrogen fusion to occur. Brown dwarfs emit heat and light from the residual heat of their formation, but they cool and fade over time.
no
it's cool
Dwarfs, such as white dwarfs or brown dwarfs, are small in size but can still be very bright because they have high temperatures that produce intense luminosity. The brightness of a dwarf is determined by its surface temperature, not its physical size. Therefore, even though dwarfs are smaller than the sun, their high temperatures allow them to emit significant amounts of light.
No Brown Dwarfs are too small to be considerred a star.
Dying stars eventually shrink into white dwarfs (which as they age eventually become red dwarfs and then brown dwarfs - but this takes an extremely long time).
Brown dwarfs are failed stars, so they don't count. Red dwarfs are the kings when it comes to dimness
Black dwarfs have the lowest surface temperature.
Those are dwarf stars, which start out as white dwarfs and as they (very slowly) cool, become red dwarfs and eventually brown dwarfs.
Somewhat confusingly, there are no "medium" stars. Stars are either dwarfs or giants. Dwarf stars (class V) come in all types: O, B, A, F, G, K, and M. There are also class VII "white dwarfs", probably better called "degenerate dwarfs" which are distinct from AV stars. In the first place, they really are small (about the size of Earth); the smallest red dwarfs are much larger, and even the so-called "brown dwarfs" are around the size of Jupiter (though much more massive). Also, they're not part of the main sequence.
Brown dwarfs are substellar objects that are larger and more massive than planets like Jupiter. They are not massive enough to sustain nuclear fusion in their cores, which is a defining characteristic of stars. Jupiter, on the other hand, is a gas giant planet in our solar system.
The name "green dwarf" is not typically used in astronomy to describe a type of star. Stars are classified based on their spectral characteristics which determine their color. Common types include red dwarfs, white dwarfs, and brown dwarfs, but not green dwarfs.
Brown dwarfs are heated primarily due to the compression of their interiors and are hot enough to glow. Some the the more massive brown dwarfs may also fuse deuterium, an isotope of hydrogen, for a short period after they form.