This artist's concept depicts giant planets circling between belts of
dust. Scientists think the star system HD 95068 may have a planetary
architecture similar to this. While the star system's two dust belts are
known, along with one massive planet, more giant planets may lurk
unseen. Image credit: NASA/JPL-Caltech. Larger image
This diagram illustrates two similar star systems, HD 95086 and HR 8799.
Evidence from NASA's Spitzer Space Telescope has pointed to the
presence of two dust belts in each system: warm, inner belts similar to
our solar system's asteroid belt, and cool, outer belts like our Kuiper
belt of icy comets. Image credit: NASA/JPL-Caltech. Full image and caption
Researchers studying what appears to be a beefed-up version of our
solar system have discovered that it is encased in a halo of fine dust.
The findings are based on infrared data from NASA's Spitzer Space
Telescope and the European Space Agency's Herschel Space Observatory, in
which NASA is a partner.
The dusty star system, called HD 95086, is located 295 light-years
from Earth in the constellation Carina. It is thought to include two
belts of dust, which lie within the newfound outer dust halo. One of
these belts is warm and closer to its star, as is the case with our
solar system's asteroid belt, while the second belt is cooler and
farther out, similar to our own Kuiper belt of icy comets.
"By looking at other star systems like these, we can piece together
how our own solar system came to be," said Kate Su, an associate
astronomer at the University of Arizona, Tucson, and lead author of the
paper.
Within our solar system, the planets Jupiter, Saturn, Uranus and
Neptune are sandwiched between the two dust belts. Scientists think
something similar is happening in the star system HD 95086, only on
larger scales. One planet, about five times the mass of Jupiter, is
already known to sit right inside HD 95086's cooler belt. Other massive
planets may be lurking between the two dust belts, waiting to be
discovered.
Studies like this from Spitzer and Herschel point the way for
ground-based telescopes to snap pictures of such planets in hiding, a
technique referred to as direct imaging. The one planet known to exist
in HD 95086 was, in fact, discovered and imaged using this technique in
2013. The images aren't sharp because the planets are so faint and far
away, but they reveal new information about the global architecture of a
planetary system.
"By knowing where the debris is, plus the properties of the known
planet in the system, we can get an idea of what other kinds of planets
can be there," said Sarah Morrison, a co-author of the paper and a PhD
student at the University of Arizona. She ran computer models to
constrain the possibilities of how many planets are likely to inhabit
the system. "We know that we should be looking for multiple planets
instead of a single giant planet."
To learn what HD 95086 looks like, the astronomers turned to a
similar star system called HR 8799. It too has an inner and outer belt
of debris surrounded by a large halo of fine dust, and four known
planets between the belts -- among the first exoplanets, or planets
beyond our solar system, to be directly imaged.
Comparing data from the two star systems hints that HD95086, like its
cousin HR 8799, is a possible home to multiple planets that have yet to
be seen. Ground-based telescopes might be able to take pictures of the
family of planets.
Both HD 95086 and HR 8799 are much younger and dustier than our solar
system. When planetary systems are young and still forming, collisions
between growing planetary bodies, asteroids and comets kick up dust.
Some of the dust coagulates into planets, some winds up in the belts,
and the rest is either blown out into a halo, or funneled onto the star.
Herschel and Spitzer are ideally suited to study the dust structures
in these systems, which glow at the infrared wavelengths the telescopes
detect.
The researchers will present the findings at the Division for
Planetary Science Meeting of the American Astronomical Society held in
Tucson, Arizona from Nov. 8 to 15.
Read more about the research at: http://uanews.org/story/baby-photos-of-a-scaled-up-solar-system
Other coauthors of the paper include Zoltan Balog at the Max-Planck
Institute of Astronomy, Heidelberg, Germany, and Renu Malhotra, Paul
Smith and George Rieke of the University of Arizona.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the
Spitzer Space Telescope mission for NASA's Science Mission Directorate,
Washington. Science operations are conducted at the Spitzer Science
Center at the California Institute of Technology in Pasadena. Spacecraft
operations are based at Lockheed Martin Space Systems Company,
Littleton, Colorado. Data are archived at the Infrared Science Archive
housed at the Infrared Processing and Analysis Center at Caltech.
Caltech manages JPL for NASA. For more information about Spitzer, visit: http://www.nasa.gov/spitzer
Herschel is a European Space Agency mission, with science instruments
provided by consortia of European institutes and with important
participation by NASA. While the observatory stopped making science
observations in April 2013, after running out of liquid coolant as
expected, scientists continue to analyze its data. NASA's Herschel
Project Office is based at JPL. JPL contributed mission-enabling
technology for two of Herschel's three science instruments. The NASA
Herschel Science Center, part of the Infrared Processing and Analysis
Center, supports the U.S. astronomical community. More information is
online at: http://www.nasa.gov/herschel
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Source: JPL-Caltech
