CoRoT Results

Darkness Nova wrote:Any more updates on the potential 1.7 earth radius one or was it alot larger?

I e-mailed someone, I forgot who now, a few months back and haven't got a response about the 1.7 Earth-radius planet. But no updates have been provided.

Darkness Nova wrote:Ohh this is all interesting and quite thoroughly done. The lack of au data makes it confusing however. I have to actually try and fail to figure out how far they really are from the star.

Here's the updated table with AU values now, provided by various papers over the past year or so. Note that the semi-major axis of CoRoT-Exo-5 b hasn't been given in any papers yet. But if you assume CoRoT-Exo-5 has one solar mass (I'm unsure where that figure comes from...), you can find it by plugging stuff in,

keeping all of your units at base units.

where :
a is the semi-major axis (metres)
Mu is equal to GM, which is the gravitational constant multiplied by the mass of the star (kilograms).



Doing the math, I get 0.05295 AU. Anyway here's that table.

Star	Planet	Mass	P (d)	Radius	a (AU)
CoRoT-Exo-1	b	1.03 J	1.5089557 d	1.49 J	0.0254
CoRoT-Exo-2	b	3.31 J	1.7429964 d	0.83 J	0.0281
CoRoT-Exo-3	b	20.2 J	4.25 d	0.97 J	0.052
CoRoT-Exo-4	b	1.1 J	9.20205 d	1.2 J	0.09
CoRoT-Exo-5	b	0.67 J	4.03 d	1.2 J	?

First CoRoT International Symposium
http://www.symposiumcorot2009.fr/

February 2nd - 5th 2009

Actually the relevant mass in the orbital radius equation is the total mass of the star and planet added together:

a³ = G(M+m)T²/(4π²)

Admittedly, this doesn't make much of a difference if m << M.

CoRoT-Exo-4 b is indeed not exactly synchronized with it's parent star.
http://www.aanda.org/index.php?option=article&access=standard&Itemid=129&url=/articles/aa/abs/2008/35/aa10246-08/aa10246-08.html

Abstract wrote:We determine the periods of the planetary orbit and star's rotation of 9.20205 $\pm$ 0.00037 and 8.87 $\pm$ 1.12 days respectively, which is consistent with this being a synchronised system.

Sirius_Alpha wrote:CoRoT-Exo-4 b is indeed not exactly synchronized with it's parent star.

True the determination of the planetary period and the determination of the star's rotation period do not yield the exact same value, but the synchronised case does lie within the uncertainties. That is why they say it is consistent with being synchronised.

Oh... yeah you're right... apparently I misread that pretty badly. I saw "inconsistent" instead of "consistent".

CoRoT-Exo-3 updated. According to the Extrasolar Planets Encyclopaedia:

Value	Previous	Updated
Distance	-	680 ± 160 pc
Mass	1.27 M_sol	1.37 M_sol
Age	0.85 Gyr	2 Gyr
Temp	6630 K	6740 K
Star Radius	1.305 R_sol	1.56 R_sol
[Fe/H]	-0.05	-0.02
Planet Radius____	0.97 R_Jup____	1.008 R_Jup

And thus the density comes down again, from 32.46 g/cm^3 to 28.93 g/cm^3 (based on density formula).

Decrease in the planet/star radius ratio which is interesting, more than compensated for by the change in the radius estimation for the star.

Uncertainties in stellar radii are one of the major sources of uncertainties in exoplanetary radii.

CoRoT-Exo-3 paper is out now.
http://exoplanet.eu/papers/CoRoT-3.pdf (pdf)

Well, it is amusing to note that after the initial "have we discovered a new class of object?" announcement and discussions of "compact brown dwarfs"...

As illustrated in Fig 10, CoRoT-Exo-3b parameters are in good agreement with the expected mass-radius relationship on the low-mass tail of these substellar objects.

Planet news from the Dynamics of Cats blog... COROT has apparently found a planet with radius < 2 Re!

What's more, HARPS has detected tens of new planets with m < 50 Me and 40+ with m < 30 Me.

jyril wrote:Planet news from the Dynamics of Cats blog... COROT has apparently found a planet with radius < 2 Re!

Yeah those guys from CoRoT have been teasing us with that for a long time. I've decided to quit biting. You'll find that specific object was the topic of discussion earlier in this thread, where I posted its light curve. About the HARPS stuff, yeah, we were told about ~30 candidates like that a while ago, which apparently HD 40307 and company were supposed to be the first taste of.

I fail to understand why they tease us with these things so?

If they don't want to publish it in fear of it being stolen by others keep it under wraps if they've taken care of that THEN TELL US ALREADY!!!!

They're trying to make certain that their conclusions are accurate.

I think the failing with the CoRoT team is not publishing their data too late, but telling us of it too early.

Remember that HD 40307 was studied for like two years even after they believed they had a 3-planet model, all for the sake of gathering more data to be sure.