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  #181 (permalink)  
Old 13-December-2007, 03:35 PM
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How many exoplanets would you guess CoRoT might introduce? [I want 4. ]
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  #182 (permalink)  
Old 15-December-2007, 07:44 PM
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And now for something completely different:
  • GD 66b, the first extrasolar planet around a white dwarf (m = 2.11 MJ, a = 2.356 AU, p = 1650 d, e = 0).
The discovery was based on the timing of stellar oscillations. Yet another method based on the Doppler effect.
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  #183 (permalink)  
Old 15-December-2007, 08:06 PM
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Quote:
Originally Posted by Kullat Nunu View Post
And now for something completely different:
  • GD 66b, the first extrasolar planet around a white dwarf (m = 2.11 MJ, a = 2.356 AU, p = 1650 d, e = 0).
The discovery was based on the timing of stellar oscillations. Yet another method based on the Doppler effect.
That's cool. Here's Fergal Mullally and team's, power point presentation. It shows how the orbital inclination is obtainable, too. [I like the more appropriate blue color for the white dwarf, too. ]
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  #184 (permalink)  
Old 02-January-2008, 09:01 PM
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Originally Posted by George View Post
How many exoplanets would you guess CoRoT might introduce? [I want 4. ]
You got one.

A hot Jupiter, but not as typical as it seems. It is unusually massive (3.53 MJ) for such a large planet (1.429 RJ).

Let's hope the CoRoT team gets lots of observation time to conduct RV confirmations...
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  #185 (permalink)  
Old 02-January-2008, 09:04 PM
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Now this is interesting... a 8-10 million years old hot Jupiter around the low-mass star TW Hydrae (Space.com article). The system is so young that the protoplanetary disk has not yet evaporated. Youngest planetary system by the factor of over 10.
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  #186 (permalink)  
Old 03-January-2008, 03:43 AM
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Quote:
Originally Posted by Kullat Nunu View Post
You got one.
So much for my simplified extrapolation. It predicted 62 exoplanet discoveries for 2007, and we only had 61.

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Now this is interesting... a 8-10 million years old hot Jupiter around the low-mass star TW Hydrae (Space.com article). The system is so young that the protoplanetary disk has not yet evaporated. Youngest planetary system by the factor of over 10.
Another Wow moment! I wonder if it is migrating.
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  #187 (permalink)  
Old 03-January-2008, 06:33 AM
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Another Wow moment! I wonder if it is migrating.
Looks like it's already migrated. It orbits ten times closer than Mercury's distance from the sun.
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  #188 (permalink)  
Old 03-January-2008, 12:16 PM
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Yes, and there is evidence it has partially cleared the protoplanetary disk in the process. The discovery of TW Hya b is a major one.

It is also good to know that the mass 9.8 MJ is the actual mass of the planet, based on the reasonable assumption that the planet orbits at the same plane as the protoplanetary disk. The inclination of the disk is 7°, which means we see it almost face-on.
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  #189 (permalink)  
Old 03-January-2008, 02:15 PM
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I am curious if there is still enough disk remaining to degrade its orbit, or if there is enough T-Tauri like tantrums that would cause migration, or both. At such an early age for the system, perhaps migration is likely.

[V838 Mon comes to mind ever since Cress et. al. proposed, in their paper, the idea that the flashes (light echos) may have been caused by planetary plunges into the star.]
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Lighten up! This is a stellar board! Author: duh.

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  #190 (permalink)  
Old 04-January-2008, 08:26 PM
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Maybe it didn't migrate at all or very little.
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  #191 (permalink)  
Old 04-January-2008, 09:22 PM
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Yes, that would seem possible.

If it is migrating, could we not detect it over a few year span?
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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.
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  #192 (permalink)  
Old 05-January-2008, 05:21 AM
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Maybe it didn't migrate at all or very little.
Current scientific thinking is that it is impossible for a gas giant to form so class to its star. As for seeing it migrate, I'm pretty sure that migrations takes a long time by human standards.
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  #193 (permalink)  
Old 05-January-2008, 07:24 PM
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Current scientific thinking is that it is impossible for a gas giant to form so class to its star. As for seeing it migrate, I'm pretty sure that migrations takes a long time by human standards.
A decaded ago, before the extrasolar planets were discovered, then current scientific thinking said all gas giants should be outside the ice line and movies like Star Wars, which had a gas giant inside the life zone, was mere fantasy...

I'd hold off on this scientific thinking and wonder just how biased we are.
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  #194 (permalink)  
Old 05-January-2008, 08:33 PM
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Quote:
...then current scientific thinking said all gas giants should be outside the ice line...
The only difference between then and now is that we've discovered that planets can and do migrate. There is still good reason to think that giants form outside the "ice line".
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  #195 (permalink)  
Old 05-January-2008, 10:22 PM
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The only difference between then and now is that we've discovered that planets can and do migrate. There is still good reason to think that giants form outside the "ice line".
How true Yogi's malaprop, "you can see a lot by just looking". The bigger the scopes, the bigger the looks, then we'll see!
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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.
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  #196 (permalink)  
Old 07-January-2008, 03:58 PM
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Seems as if I read this a while back, but it's dated today. Apologies if it's shown up already - couldn't find the instance if so:

Exoplanet reflected light detected for the first time

Quote:
The ability to explore remote worlds in space has been enhanced through a polarization technique that allows the first ever detection of light reflected by extrasolar (exoplanet) planets. The study has been accepted for publication in Astrophysical Journal Letters.

An international team of astronomers, led by Professor Svetlana Berdyugina of ETH Zurich's Institute of Astronomy, has for the first time ever been able to detect and monitor the visible light that is scattered in the atmosphere of an exoplanet. Employing techniques similar to how Polaroid sunglasses filter away reflected sunlight to reduce glare, the team of scientists were able to extract polarized light to enhance the faint reflected starlight 'glare' from an exoplanet. As a result, the scientists could infer the size of its swollen atmosphere. They also directly traced the orbit of the planet, a feat of visualization not possible using indirect methods.
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  #197 (permalink)  
Old 09-January-2008, 06:54 PM
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AAS News

USA Today: Faraway planets collided, merged into one (from Space.com)

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An extrasolar planet about one-fourth the heft of Jupiter might have formed from the collision and merger of two planets, astronomers announced.
Known as 2M1207B, the object orbits a brown-dwarf star called 2M1207A located 170 light-years from Earth and seen in the direction of the constellation Centaurus.

Astronomers have long puzzled over the mysterious object, which seems to fall outside the spectrum of physical possibility. Its temperature, age and brightness don't match up with what astrophysical theory would predict.
Horse's mouth: CfA press release: When Worlds Collide: Have Astronomers Observed the Aftermath of a Distant Planetary Collision?

Here's an artist's concept, but won't someone please make the CG animation of this?

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  #198 (permalink)  
Old 09-January-2008, 07:05 PM
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Man, 20 yrs ago, exoplanets were all in the province of sci-fi. Now, we're finding new worlds on a semi-regular basis. How long will it be till we snap a photo of some alien planet, and catch a glint of light off SOMEBODY ELSE'S camera lens?
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  #199 (permalink)  
Old 09-January-2008, 07:23 PM
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Originally Posted by Abbadon_2008 View Post
How long will it be till we snap a photo of some alien planet, and catch a glint of light off SOMEBODY ELSE'S camera lens?
That will take a very long time. I would guess thousands of years.
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