By Dennis Overbye

January 30, 2011

The search for distant planets starts with the
vibrations of their stars, and in those vibrations lies a kind of music.

src="http://graphics8.nytimes.com/images/2011/01/31/science/31star_art/31star_art-popup.jpg">

The heart-shaped vibrations for
the star KIC12253350

Listen on the site at href="http://www.nytimes.com/2011/01/31/science/space/31star.html">http://www.nytimes.com/2011/01/31/science/space/31star.html 
size=2>under the heading "Listening to the Stars" (left side of
screen)

“We only know the planet as well as we know
the star,” said Natalie Batalha, an astronomer from San Jose State University
who works on NASA’s planet-searching satellite Kepler. To that end, Kepler
listens to the internal vibrations of stars, gleaning crucial information on
their size and structure.

By speeding up this data and transforming it
into sound waves, Kepler’s astronomers have produced a sort of iTunes sampler of
the cosmos, individual stars banging and whistling.

“Some of these are music only the Borg could
love,” said Jon Jenkins, a Kepler data analyst from the SETI Institute in
Mountain View, Calif., referring to the cybernetic foes from the “Star Trek”
series. Dr. Jenkins made the recordings presented here.

Kepler monitors the light of 156,000 stars,
checking for dips in intensity caused when their planets, if they have any, pass
in front of them. It also records high-frequency variations in stars’ light
caused by vibrations or “starquakes” in the stars themselves, from which
astronomers practicing the science of asteroseismology can deduce the age and
size of the star.

By knowing how big the star really is, and
the dips in light from the planetary crossings, astronomers can measure the
exact size of any planet.

In audio clips, several weeks’ worth of
Kepler measurements of a star have been compressed into a few seconds.

Kepler 10b is the first rocky planet to be
discovered by Kepler. The first audio contains only the vibrations of Kepler
10b’s star. The next audio clip has the sound of the planet going by as a “wump
wump wump.”

KIC1268220 is an eclipsing binary, in which a
pair of stars pass in front of each other, producing a bass thumping of eclipses
along with a “whistling forest” of stellar vibrations, in the words of Dr.
Jenkins.

KIC12253350 is an unusual star. On a graph,
its oscillations follow a heart-shaped envelope. The Kepler astrophysicists do
not understand why, but they liked it so much that they put the heart-shaped
oscillations on a T-shirt with a quotation about the cosmos by Carl Sagan: “For
such small creatures such as we the vastness is bearable only through love.”

# # #