References & Sources

Elliptical orbits may be planetary norm

Astronomers have found six additional planets orbiting nearby, sunlike stars, bringing to 28 the number of known extrasolar planets and suggesting that near-circular orbits like Earth’s are unusual.

References:

Vogt, S.S., G.W. Marcy, R.P. Butler, and K. Apps. 1999. Six new planets from the Keck Precision Velocity Survey. Available at http://xxx.lanl.gov/abs/astro-ph/9911506.

Further Readings:

Cowen, R. 1999. Solar system planets: Freaks of nature? Science News 155(Jan. 30):79.

Sources:

Kevin Apps
University of Sussex at Brighton
Department of Physics and Astronomy
Falmer, Brighton BN1 9QJ
United Kingdom

R. Paul Butler
Carnegie Institution
Department of Terrestrial Magnetism
5241 Broad Branch Road, N.W.
Washington, DC 20015-1305

Geoffrey W. Marcy
University of California, Berkeley
Department of Astronomy
Berkeley, CA 94720

Steven S. Vogt
University of California, Santa Cruz
UCO/Lick Observatory
Santa Cruz, CA 95064

From Science News, Vol. 156, No. 24, December 11, 1999, p. 377. Copyright © 1999, Science Service.