Kepler Finds a Very Wobbly Planet
 
Feb. 4, 2014:  Imagine living on a planet with seasons so erratic you would
hardly know whether to wear Bermuda shorts or a heavy overcoat. That is the
situation on a weird, wobbly world found by NASA's planet-hunting Kepler space
telescope.
 
The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin
axis, much like a child's top. The tilt of the planet's spin axis can vary by
as much as 30 degrees over 11 years, leading to rapid and erratic changes in
seasons. In contrast, Earth's rotational precession is a relatively tame 23.5
degrees over 26,000 years. Researchers are amazed that this far-off planet is
precessing on a human timescale.
 
http://www.nasa.gov/sites/default/files/14-041_kepler_p1412aw_0.jpg
 
This illustration shows the unusual orbit of planet Kepler-413b around a close
pair of orange and red dwarf stars. The planet's 66-day orbit is tilted 2.5
degrees with respect to the plane of the binary star's orbit. The orbit of the
planet wobbles around the central stars over 11 years. Image Credit:  NASA,
ESA, and A. Feild (STScI)
 
Kepler 413-b is located 2,300 light-years away in the constellation Cygnus. It
circles a close pair of orange and red dwarf stars every 66 days. The planet's
orbit around the binary stars appears to wobble, too, because the plane of its
orbit is tilted 2.5 degrees with respect to the plane of the star pair's
orbit. As seen from Earth, the wobbling orbit moves up and down continuously.
 
Kepler finds planets by measuring the dimming of starlight when a planet
passes in front of its parent sun--or, in this case, suns because the planet
circles a pair of stars. Normally, planets transit like clockwork. Astronomers
using Kepler discovered the wobbling when they found an unusual pattern of
transiting for Kepler-413b.
 
"Looking at the Kepler data over the course of 1,500 days, we saw three
transits in the first 180 days -- one transit every 66 days -- then we had 800
days with no transits at all. After that, we saw five more transits in a row,"
said Veselin Kostov, the principal investigator on the observation. Kostov is
affiliated with the Space Telescope Science Institute and Johns Hopkins
University in Baltimore, Md. "[The next transit visible from Earth is not
predicted to occur until 2020.]"
 
Astronomers are still trying to explain why this planet is out of alignment
with its stars. There could be other planetary bodies in the system that
tilted the orbit. Or, it could be that a third star nearby that is a visual
companion may actually be gravitationally bound to the system and exerting an
influence.
 
"Presumably there are planets out there like this one that we're not seeing
because we're in the unfavorable period," said Peter McCullough, a team member
with the Space Telescope Science Institute and Johns Hopkins University. "And
that's one of the things that Veselin is researching: Is there a silent
majority of things that we're not seeing?"
 
Even with its changing seasons, Kepler-413b is too warm for life as we know
it. Because it orbits so close to the stars, its temperatures are too high for
liquid water to exist, making it inhabitable. It also is a super Neptune -- a
giant gas planet with a mass about 65 times that of Earth -- so there is no
surface on which to stand.
 
Credits:
Production editor: Dr. Tony Phillips | Credit: Science@NASA
 
More information:
NASA's Ames Research Center at Moffett Field, Calif., is responsible for the
Kepler mission concept, ground system development, mission operations and
science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
managed Kepler mission development. Ball Aerospace & Technologies Corp. in
Boulder, Colo., developed the Kepler flight system and supports mission
operations with the Laboratory for Atmospheric and Space Physics at the
University of Colorado in Boulder. The Space Telescope Science Institute in
Baltimore archives, hosts and distributes Kepler science data. Kepler is
NASA's 10th Discovery mission and was funded by the agency's Science Mission
Directorate.
 
For images and more information about Kepler-413b, visit: http:/
hubblesite.org/news/2014/12
 
For more information about the Kepler space telescope, visit: ht
p://www.nasa.gov/kepler
 
 
Regards,
 
Roger

--- D'Bridge 3.98
 * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)