Explanation:
This cosmic snapshot
composed with image data from NASA's Wide-field
Infrared Survey Explorer
(WISE)
satellite captures a multitude of
faint stars and distant galaxies toward the constellation Lyra at
wavelengths longer than visible light.
But the object circled at the center is not quite a star.
Cataloged as WISE 1828+2650, it lies within 40 light-years of the Sun
and is currently the
coldest brown dwarf known.
A brown dwarf begins like a star, with the
gravitational collapse of a
dense cloud of gas and dust, but is not massive enough to achieve the
core temperatures and densities that trigger
hydrogen
fusion, the stable source of a star's energy.
Instead the failed star ultimately cools and emits most of its light at
infrared wavelengths.
Remarkably, brown dwarfs are
roughly the size of the planet Jupiter.
How cold is WISE 1828+2650?
While brown dwarfs
have measured surface temperatures of up to 1,400
degrees C (2,600 degress F), this brown dwarf ,
assigned to
spectral class Y,
has the estimated temperature of a warm room, less than
about 27 degrees C (80 degrees F).
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