Methane Dwarf
Credit:
SDSS Collaboration
While hunting through
Sloan Sky Survey
data in search of
distant quasars,
Princeton astronomers Xiaohui Fan and Michael Strauss came
upon an undiscovered type of object very nearby - now dubbed
a methane dwarf.
Marked by white lines in
this recently released image, the isolated,
faint, but extremely red methane dwarf lies only 30 or so light-years
away in the constellation Ophiuchus.
Intermediate in size between
a star and a planet, it is thought to be
about 10 to 70 times as massive as Jupiter.
The moniker "methane dwarf" was derived from the strong signature of
methane gas in
the object's spectrum.
Along with the red color, the presence of
methane (CH4) indicates
that this object is cool - cooler
than brown dwarfs
which lack the strong methane signature
yet are the only other known objects
in this mass range.
Subsequent observations have now raised the total to three detected
methane dwarfs, but because they are so difficult to find
so far no one knows if they are rare or common in our Galaxy.