Around Tau Ceti is no analogue of Jupiter

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Around Tau Ceti is no analogue of Jupiter

Post by Borislav on 14th April 2010, 9:22 am

http://online.kitp.ucsb.edu/online/exoplanets_c10/marcy/pdf/Marcy_ExoPlanetsConf_KITP.pdf


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Re: Around Tau Ceti is no analogue of Jupiter

Post by Borislav on 14th April 2010, 10:01 am

I'm beginning to believe theorists, who predict that giant planets have only 20 percent of stars Sun-like stars.
Systems similar to the Solar System, only rare exceptions. Sad

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Re: Around Tau Ceti is no analogue of Jupiter

Post by Edasich on 14th April 2010, 10:02 am

No Jovian No cry. *lol*

Maybe more "Earths" and telluric planets hidden... Wink

However I think this should be redirected on Planetology subforum (Mechanics, whatever) rather in News.

No discovery news about Tau Ceti so far. Though I'm eagerly awaiting one since long time.
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Lazarus on 14th April 2010, 1:59 pm

IIRC Tau Ceti is seen nearly pole-on, so it may be that it is a bad target for RV planets anyway. (Assuming any planetary system there is drawn from the near-aligned population rather than the Kozai/scattered one)
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Borislav on 14th April 2010, 2:20 pm

Edasich wrote:However I think this should be redirected on Planetology subforum (Mechanics, whatever) rather in News.
Sorry, moved please.

Lazarus wrote:IIRC Tau Ceti is seen nearly pole-on, so it may be that it is a bad target for RV planets anyway. (Assuming any planetary system there is drawn from the near-aligned population rather than the Kozai/scattered one)

Thank you. Now read.
http://adsabs.harvard.edu/abs/2004MNRAS.351L..54G
Combined with the known stellar rotation period and radius (Saar & Osten 1997; Di Folco et al. 2004), the implied inclination of the stellar equator is 0-40 degree angle from the sky plane.

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Re: Around Tau Ceti is no analogue of Jupiter

Post by Sirius_Alpha on 14th April 2010, 2:30 pm

Moved due to popular demand.

I am guessing we may need to wait for a SIM-style mission until planets are detected there.

Anyone know what the inclination is of the Tau Cet disk?

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Re: Around Tau Ceti is no analogue of Jupiter

Post by Lazarus on 14th April 2010, 2:39 pm

The paper Borislav linked quotes that the best-fitting thin disc model is nearly edge-on (60-90 degrees), but there are considerable uncertainties, and it could be that what is being seen are brightness features in a near pole-on disc.
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Borislav on 14th April 2010, 2:54 pm

Lazarus wrote:The paper Borislav linked quotes that the best-fitting thin disc model is nearly edge-on (60-90 degrees), but there are considerable uncertainties, and it could be that what is being seen are brightness features in a near pole-on disc.

Think soon space telescope Herschel finally clarify this issue.

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Re: Around Tau Ceti is no analogue of Jupiter

Post by Edasich on 25th April 2010, 6:23 am

Am I missing something?

Shutdown of melting on old, stagnant lid planets: All our melting models predict that stagnantlid planets planets older than Earth cease melting and volcanic activity (x3.3-5, but see caveatsin x6.2). Therefore, observed volcanism on rocky planets > 8 Gya would provide some supportfor plate tectonics { if and only if tidal heating could be shown to be small. A candidate planetary system has been identifieed around Tau Ceti (Marcy 2002), a 10 Gya star at 3.65parsec, and may provide an early test of this prediction

I found no Marcy 2002 reference. And link provided in paper is broken.
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Lazarus on 25th April 2010, 7:57 am

Link works fine for me, you have to replace the (underscore) with an actual underscore Smile

Repaired link

I think this one has been mentioned before here: two planets with m*sin(i) close to Neptune mass in short period orbits. Given nothing solid has come of this one for 8 years or so, and the continued use of Tau Ceti as an RV-stable star during that time, I wouldn't read too much into it.
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Edasich on 25th April 2010, 12:41 pm

Thanks, Lazarus.
I "re-exhumed" this topic because this recent article states the planetary system is confirmed.

Geodynamics and rate of volcanism on massive earth-like planets.

It does also add this statement:

If volcanism is detected in the Tau Ceti system, and tidal forcing can be shown to be weak, this would be evidence for plate tectonics.

It's not so serious to refer to the system as confirmed.
Especially after astrometry failure.

Even putting the latest RV set in Systemics I don't get any convincing orbital solutions and sure I don't find mentioned peaks at 19.3 and 61 days.
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Re: Around Tau Ceti is no analogue of Jupiter

Post by Lazarus on 25th April 2010, 12:56 pm

As far as I can tell, it does not state the planetary system is confirmed: it merely states a candidate planetary system was identified. I don't see this as implying a solid discovery claim.
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Re: Around Tau Ceti is no analogue of Jupiter

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