Each figure shows an artist's rendition comparing brown dwarfs to stars
and planets. All objects are plotted to the same scale. On the far left
is the limb of the Sun. To its right is shown a very low mass star (a
so-called "late-M dwarf"), a couple of brown dwarfs (a hotter
"L dwarf"
and a cooler "T dwarf"), and the planet Jupiter. These objects have
masses ranging from 1050 times that of Jupiter (for the
Sun) through 75,
65, 30, and 1 Jupiter mass for the late-M dwarf, L dwarf, T dwarf,
and
Jupiter, respectively. The colors of the brown dwarfs
are chosen to
match an age of 1 billion years. Despite the range in mass, all four of
the low-mass objects are approximately the same size, ten times smaller
than the diameter of the Sun.
Figure 1
IMAGE CAPTION TO FIGURE 1
Figure 1 shows how these objects might appear to the human eye: the
M
and L dwarfs are red, while the T dwarf
is dimly magenta, due to lack of
light -- actually absorptions by sodium and potassium atoms -- in the
green portion of the spectrum.
Figure 2
IMAGE CAPTION TO FIGURE 2
Figure 2 shows the same objects as they might appear to eyes sensitive
to near-infrared light. Here the M and
L dwarfs are slightly orange or
red compared to the Sun, but the T dwarf is distinctly
blue due to a
lack of light in the "green" and "red" caused by absorption from
methane.
Methane is also abundant in the atmosphere of Jupiter and this, along
with the clouds and bands of other complex molecules, gives it
alternating patches of pink and blue.
ARTWORK CREDIT
Artist's renditions by Dr. Robert Hurt of the Infrared Processing and
Analysis Center.
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