Exoplanet Discoveries, discussion of the latest finds |
Exoplanet Discoveries, discussion of the latest finds |
Guest_PhilCo126_* |
Apr 21 2009, 11:10 AM
Post
#1
|
Guests |
Well-known exoplanet researcher Dr Michel Mayor ( discoverer of Peg 51b with Dr Didier Queloz in 1995 ) today announced the discovery of the lightest exoplanet found so far. The planet, “e”, in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist:
http://www.eso.org/public/outreach/press-r...9/pr-15-09.html |
|
|
Dec 6 2009, 05:07 PM
Post
#2
|
|
Senior Member Group: Members Posts: 1452 Joined: 26-July 08 Member No.: 4270 |
Of course it's more exciting, but only in the "All stars are actually anti-matter/matter reaction driven" sort of sense. There's no reason to support it, and there's already other ideas that better explain what is observed.
Planet hosts are lithium poor. Planets not known to have stars are lithium rich. (anti)correlation has something to do with planets (or planet formation). This trend only shows up for stars within +/- 100 K of Sol's effective temperature. (anti)correlation has something to do with the structures of stars +/- 100 K of Sol's effective temperature. Even in our solar system, the planets (or the process of their formation) were able to cause Sol to become lithium poor. There is no evidence for any of our planets having exploded in the past. Does the idea of a exploding companions explain why only near-stellar Teff stars display this correlation? Does it explain why binary stars in the same temperature range do not? Is there any evidence for planetary companions blasting their neighbors and screaming? Consider the 16 Cygni system. Two sun-like stars: the lithium-poor star hosts a planet. The lithium-rich star hosts an M-dwarf. -------------------- -- Hungry4info (Sirius_Alpha)
|
|
|
Dec 6 2009, 09:28 PM
Post
#3
|
|
Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
1 (anti)correlation has something to do with planets (or planet formation). 2 (anti)correlation has something to do with the structures of stars +/- 100 K of Sol's effective temperature. 3 There is no evidence for any of our planets having exploded in the past. 4 Is there any evidence for planetary companions blasting their neighbors and screaming? 1 - Agreed. 2 - Agreed. 3 - I didn't say that, and neither did Fred Hoyle. The explosion would have predated (and lead to) planet formation. 4 - I didn't say 'scream' either(!) I said scram, as in 'rapidly leave the area'. There has also been quite a lot written over the years about the trauma to a close companion star when a supernova occurs, and about binaries becoming unbound following stellar explosions. I don't think it's far fetched to imagine that the trauma might involve lithium destruction for certain classes of star but not others. 16 Cygni B is around 1000AU from the AC pair, maybe far enough for a supernova to destroy the lithium in one but not the other. There may be better theories as you say, but as you also say they are not complete and there is no clear winner yet so I don't think broader speculation is out of order at this stage. |
|
|
Lo-Fi Version | Time is now: 23rd September 2024 - 11:02 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |