 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Planets Galore: 12 New Discoveries Announced
Pasadena CA (JPL) Feb 17, 2005 The past four weeks have been heady ones in the planet-finding world: Three teams of astronomers announced the discovery of 12 previously unknown worlds, bringing the total count of planets outside our solar system to 145. Just a decade ago, scientists knew of only the nine planets - those in our local solar system. In 1995, improved detection techniques produced the first solid evidence of a planet circling another star. A proliferation of discoveries followed, and now dozens of ongoing search efforts around the globe add steadily to the roster of worlds. Most of these planets differ markedly from the planets in our own solar system. They are more similar to Jupiter or Saturn than to Earth, and are considered unlikely to support life as we know it. The news of the past four weeks has included:
All were discovered as part of the High Accuracy Radial velocity Planet Search (HARPS), an ongoing search program based at La Silla Observatory in Chile.
The U.S. team based its finding on observations obtained at the W.M. Keck Observatory in Hawaii, which is jointly operated by the University of California and Caltech. Observation time was granted by both NASA and the University of California.
A pulsar is a dense and compact star that forms from the collapsing core left over from the death of a massive star. The new pulsar planet is the fourth to be discovered; all orbit the same pulsar, named PSR B1257+12. Because the planets around the pulsar are continually strafed by high-energy radiation, they are considered extremely inhospitable to life. (Note: The currentl planet count posted on this website includes only planets around normal stars.)
Two methods of detection The pulsar planet was discovered by observing the neutron star's pulse arrival times, called pulsar timing. Variations in these pulses give astronomers an extremely precise method for detecting the phenomena that occur within a pulsar's environment. The gas-giant planets were detected using the radial velocity method, which infers the presence of an unseen companion because of the back-and-forth movement induced in the host star. This movement is detectable as a periodic red shift and blue shift in the star's spectral lines. (For more about this method, see the article Finding Planets.) The names of the new planets around main sequence stars are:
Email This Article Comment On This Article Related Links SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Lands Beyond Beyond - extra solar planets - news and science Life Beyond Earth
Study Highlights Role Of Hit-And-Run Collisions In Planet Formation
Santa Cruz CA (SPX) Jan 12, 2006Hit-and-run collisions between embryonic planets during a critical period in the early history of the Solar System may account for some previously unexplained properties of planets, asteroids, and meteorites, according to researchers at the University of California, Santa Cruz, who describe their findings in a paper to appear in the January 12 issue of the journal Nature. |
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
