MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
Contact: Jane Platt (818) 354-0880
FOR IMMEDIATE RELEASESeptember 28, 2000
ASTRONOMERS IMPROVE "COSMIC YARDSTICK"
Researchers using a sophisticated testbed at Caltech's
Palomar Observatory near San Diego, Calif., have achieved the
best-ever distance measurement to a type of star known as a
Cepheid variable. These results improve the "cosmic yardstick"
used to infer the size and shape of the universe.
In the September 28 issue of the journal Nature, astronomers
from NASA's Jet Propulsion Laboratory; the California Institute
of Technology; and the JPL/Caltech Infrared Processing and
Analysis Center, all in Pasadena, determined a distance to the
star Zeta Geminorum in the Gemini constellation of 1,100 light
years. The improvement was made possible by the Palomar Testbed
Interferometer, designed and built by JPL researchers. The
device combines light gathered by two telescopes to produce a
very sharp image normally obtainable only with a much larger
Details on this discovery and the testbed are available at
JPL is managed for NASA by Caltech, Pasadena, Calif.