June 15, 2010: NASA's Kepler Mission has released 43 days of
science data on more than 156, 000 stars. These stars are being
monitored for subtle brightness changes as part of an ongoing search
for Earth-like planets outside of our solar system.
Astronomers will use the new data to determine if orbiting planets are
responsible for brightness variations in several hundred stars. These
stars make up a full range of temperatures, sizes and ages. Many of
them are stable, while others pulsate. Some show starspots, which are
similar to sunspots, and a few produce flares that would sterilize
their nearest planets.
Kepler, a space observatory, looks for the data signatures of planets
by measuring tiny decreases in the brightness of stars when planets
cross in front of, or transit them. The size of the planet can be
derived from the change in the star's brightness.
The 28-member Kepler science team also is using ground-based
telescopes and the Hubble Space Telescope and Spitzer Space Telescope
to perform follow-up observations on a specific set of 400 objects of
interest. The star field that Kepler observes in the constellations
Cygnus and Lyra can only be seen from ground-based observatories in
spring through early fall. The data from these other observations
will determine which of the candidates can be identified as planets.
That data will be released to the scientific community in February
2011.
Without the additional information, candidates that are actual planets
cannot be distinguished from false alarms, such as binary stars --
two stars that orbit each other. The size of the planetary candidates
also can be only approximated until the size of the stars they orbit
is determined from additional spectroscopic observations made by
ground-based telescopes.
"I look forward to the scientific community analyzing the data and
announcing new exoplanet results in the coming months, " said Lia
LaPiana, Kepler's program executive at NASA Headquarters in
Washington.
"This is the most precise, nearly continuous, longest and largest data
set of stellar photometry ever, " said Kepler Deputy Principal
Investigator David Koch of NASA's Ames Research Center in Moffett
Field, Calif. "The results will only get better as the duration of
the data set grows with time."
Kepler will continue conducting science operations until at least
November 2012, searching for planets as small as Earth, including
those that orbit stars in a warm habitable zone where liquid water
could exist on the surface of the planet. Since transits of planets
in the habitable zone of solar-like stars occur about once a year and
require three transits for verification, it is expected to take at
least three years to locate and verify an Earth-size planet.
"The Kepler observations will tell us whether there are many stars
with planets that could harbor life, or whether we might be alone in
our galaxy, " said mission science principal investigator William
Borucki of Ames.
Ames is responsible for the ground system development, mission
operations and science data analysis. NASA's Jet Propulsion
Laboratory in Pasadena, Calif., managed the Kepler mission
development. Ball Aerospace and 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, Boulder. The Space Telescope Science
Institute in Baltimore archives, hosts and distributes the Kepler
science data.
To see the science data, visit: http://archive.stsci.edu/kepler
For more information about the Kepler mission, visit: http://www.nasa.gov/kepler
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