Dark Jupiter size object
probably lurks at the edge of the Solar System
a new analysis of observations dating back to 1898, Matese and
Whitmire confirm their original idea: About 20 percent of the
comets visible from Earth were sent by a dark, distant planet.
examining the orbits of more than 100 comets in the Minor Planet
Center database, the researchers concluded that 80 percent of
comets born in the Oort Cloud were pushed out by the galaxy’s
gravity. The remaining 20 percent, however, needed a nudge from a
distant object about 1.4 times the mass of Jupiter.
pattern only works for comets that come from the spherical outer
Oort Cloud, which extends from about 0.3 to 0.8 light-years from
the sun. Comets from the flatter, more donut-shaped inner Oort
Cloud don’t create the same distinctive pattern
“I think this whole issue will
be resolved in the next 5 to 10 years, because there’s surveys
coming on line … that will dwarf the comet sample we have today,”
he said. “Whether these types of asymmetries in the directions
that comets are coming from actually do exist or not will
definitely be hammered out by those surveys.”
We may not
have to wait that long, Matese says. An object like Tyche could be
seen directly by WISE, NASA’s infrared space telescope.
anticipate that this WISE is going to falsify or verify our
conjecture,” he said. “We just have to be patient.”
That green dot in the middle of this image might look like an emerald
amidst glittering diamonds, but it is actually a dim star belonging
to a class called brown dwarfs. This particular object is the first
ultra-cool brown dwarf discovered by WISE. Image credit:
November 09, 2010
Wide-field Infrared Survey Explorer, or WISE, has eyed its first cool
brown dwarf: a tiny, ultra-cold star floating all alone in space.
WISE is scanning the whole sky in infrared light, picking up
the glow of not just brown dwarfs but also asteroids, stars and
galaxies. It has sent millions of images down to Earth, in which
infrared light of different wavelengths is color-coded in the images.
"The brown dwarfs jump out at you like big, fat, green
emeralds," said Amy Mainzer, the deputy project scientist of
WISE at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Mainzer,
who makes jewelry in her spare time, explained that the brown dwarfs
appear like green gems in WISE images because the methane in their
atmospheres absorbs the infrared light that has been coded blue, and
because they are too faint to give off the infrared light that is
color-coded red. The only color left is green.
brown dwarfs are made up of gas -- a lot of it in the form of
methane, hydrogen sulfide, and ammonia. These gases would be deadly
to humans at the concentrations found around brown dwarfs. And they
wouldn't exactly smell pretty.
"If you could bottle up a
gallon of this object's atmosphere and bring it back to Earth,
smelling it wouldn't kill you, but it would stink pretty badly --
like rotten eggs with a hint of ammonia," said Mainzer.
Mainzer and other members of the WISE team are already
accumulating a quarry of brown dwarf candidates similar to this one.
Brown dwarfs have masses somewhere between those of a star and a
planet. They start out like stars as collapsing balls of gas, but
they lack the mass to fuse atoms together at their core and shine
with starlight. As time goes on, these lightweights cool off, until
they can only be seen in infrared light. There could be many such
objects lurking in the neighborhood of our sun, but astronomers know
of only a handful so far. WISE is expected to find hundreds,
including the coolest and closest of all.
brown dwarfs represent the perfect laboratories for studying
"They're a great test of our
understanding of atmospheric physics of planets, since they don't
have solid surfaces, and there's no big, bright sun to get in the
way," said co-author Michael Cushing, a postdoctoral fellow at
WISE's new brown dwarf is named WISEPC
J045853.90+643451.9 for its location in the sky. It is estimated to
be 18 to 30 light-years away and is one of the coolest brown dwarfs
known, with a temperature of about 600 Kelvin, or 620 degrees
Fahrenheit. That's downright chilly as far as stars go. The fact that
this brown dwarf jumped out of the data so easily and so quickly --
it was spotted 57 days into the survey mission -- indicates that WISE
will discover many, many more. The discovery was confirmed by
follow-up observations at the University of Virginia's Fan Mountain
telescope, the Large Binocular Telescope in southeastern Arizona, and
NASA's Infrared Telescope Facility on Mauna Kea, Hawaii. The results
are in press at the Astrophysical Journal.
Read more about
Spitzer Space Telescope and WISE are hunting down the coldest brown
JPL manages the Wide-field Infrared Survey
Explorer for NASA's Science Mission Directorate, Washington. The
principal investigator, Edward Wright, is at UCLA. The mission was
competitively selected under NASA's Explorers Program managed by the
Goddard Space Flight Center, Greenbelt, Md. The science instrument
was built by the Space Dynamics Laboratory, Logan, Utah, and the
spacecraft was built by Ball Aerospace & Technologies Corp.,
Boulder, Colo. Science operations and data processing take place at
the Infrared Processing and Analysis Center at the California
Institute of Technology in Pasadena. Caltech manages JPL for NASA.
More information is online at http://www.nasa.gov/wise