Skip to comments."Planemos" May Give Rise to Planets, Moons
Posted on 06/05/2006 11:08:11 PM PDT by SunkenCiv
Astronomer Ray Jayawardhana of the University of Toronto and his international team of colleagues surveyed the optical spectra of seven exoplanets in two studies. One focused on six planemos, or planetary mass objects, that float freely through space without a specific relationship to a star. The other study looked at the exoplanet locked in a binary system with a failed star that has just eight percent of the mass of our sun. The exoplanets in both studies bore the infrared emissions associated with dusty disks... Such disks are thought to be planetary nurseries, giving rise to satellites over time as the material collides and agglomerates. Because these swirling clouds are known to accompany the formation of stars, it suggests that planemos may originate in the same way--by the gravitational collapse of gas and dust... [T]he smallest of the planemos is still five times the size of Jupiter, which is more than 300 times as massive as Earth. And Jupiter most likely had a similar ring to form the classic Galilean moons, according to Jayawardhana.
(Excerpt) Read more at sciam.com ...
Stars Swallow Planets and Researchers Have ProofA light spectrum analysis of HD82943a star slightly hotter and larger than the sun, harboring its own planetary systemrevealed that it contained traces of an isotope of lithium called Lithium-6, or 6Li. Although 6Li is common in planets, it burns up quickly in stars after they are born and thus shouldn't exist in a star like HD82943... To confirm their theory, the scientists looked at another star that shared HD82943's characteristics except that it did not have planets. In keeping, they found that did not have 6Li in its spectrum. The researchers hope that this finding will help to explain how so-called exoplanets form and if this kind of cannibalism is a common process.
by Harald Franzen
May 10, 2001
Rogue Planet Find Makes Astronomers Ponder TheoryEighteen rogue planets that seem to have broken all the rules about being born from a central, controlling sun may force a rethink about how planets form, astronomers said on Thursday... "The formation of young, free-floating, planetary-mass objects like these is difficult to explain by our current models of how planets form," Zapatero-Osorio said... They are not linked to one another in an orbit, but do move together as a cluster, she said... Many stars in our own galaxy, the Milky Way, may have formed in a similar manner to the Orion stars, she said. So there could be similar, hard-to-see planets floating around free near the Solar System.
by Maggie Fox
October 5, 2000
Planet-Forming Disks Might Put the Brakes on Stars
NASA Jet Propulsion Laboratory | July 24, 2006 | Whitney Clavin
Posted on 07/31/2006 1:04:39 AM EDT by SunkenCiv