CoRoT Results

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Re: CoRoT Results

Post by Galzi on 5th August 2012, 3:53 pm

Paper of COROT-21b, an apparently doomed hot Jupiter around a faint sub-giant

CoRoT-21, a F8IV star of magnitude V=16 mag, was observed by the space telescope CoRoT during the Long Run 01 (LRa01) in the first winter field (constellation Monoceros) from October 2007 to March 2008. Transits were discovered during the light curve processing. Radial velocity follow-up observations, however, were performed mainly by the 10-m Keck telescope in January 2010.
The companion CoRoT-21b is a Jupiter-like planet of 2.26±0.33 Jupiter masses and 1.30±0.14 Jupiter radii in an circular orbit of semimajor axis 0.0417±0.0011 AU and an orbital period of 2.72474±0.00014 days. The planetary bulk density is (1.36±0.48)·103 kg m−3, very similar to the bulk density of Jupiter, and follows an M1/3 −R relation like Jupiter. The F8IV star is a sub-giant star of 1.29±0.09 solar masses and 1.95±0.2 solar radii. The star and the planet exchange extreme tidal forces that will lead to orbital decay and extreme spin-up of the stellar rotation within 800 Myr if the stellar dissipation is Q∗/k2∗ ≤ 107.


Last edited by Galzi on 26th October 2012, 11:47 am; edited 1 time in total (Reason for editing : Broken link)

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Re: CoRoT Results

Post by Galzi on 19th August 2012, 2:55 pm

Paper about COROT-16b, a bloated eccentric hot jupiter

Aims. We report the discovery of CoRoT-16b, a low density hot jupiter that orbits a faint G5V star (mV = 15.63) in 5.3523 ± 0.0002 days with slight eccentricity. A fit of the data with no a priori assumptions on the orbit leads to an eccentricity of 0.33 ± 0.1. We discuss this value and also derive the mass and radius of the planet.
Methods. We analyse the photometric transit curve of CoRoT-16 given by the CoRoT satellite, and radial velocity data from the HARPS and HIRES spectrometers. A combined analysis using a Markov chain Monte Carlo algorithm is used to get the system parameters.
Results. CoRoT-16b is a 0.535 −0.083/+0.085 MJ, 1.17 −0.14/+0.16 RJ hot Jupiter with a density of 0.44 −0.14/+0.21 g cm−3. Despite its short orbital distance (0.0618 ± 0.0015 AU) and the age of the parent star (6.73 ± 2.8 Gyr), the planet orbit exhibits significantly non-zero eccentricity.
This is very uncommon for this type of objects as tidal effects tend to circularise the orbit. This value is discussed taking into account the characteristics of the star and the observation accuracy.

The only papers still missing regards COROT-22b and the COROT 24 system.

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Re: CoRoT Results

Post by Galzi on 21st September 2012, 3:13 pm

Claire Moutou, Corot Project Investigator, at the first Kepler science conference on 5 December 2011:

http://connect.arc.nasa.gov/p5ntjd94def/

Notable the huge follow-up effort, the large majority of candidates around very faint stars, with a number of unsolved cases (hot stars, fast rotators, no RV signal detected).
Overall 545 candidates selected for follow-up, 300 solved, only 25 of them confirmed as planets. 160 candidates waiting for follow-up. They apparently aren't validating their candidates through statistical arguments like Kepler's scientists.

Interesting hints about Corot 24 system, masses of the planets (3.7 and 5 Earth radii) tentatively measured around 40 Earth masses; a third outer non-transiting planet inferred from a long-period trend in the RV data.

They're unable to explain the dearth of Neptunes detected so far, apparently in tests they recovered 80% of fake Neptune transits injected in real data. On the other hand they confirm an under-detection of transiting Super-Earths, with only 35% of transits recovered by algortihms. Maybe the extra-activity of Solar-like stars is affecting the detection performance of the mission, like happened to Kepler.

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Re: CoRoT Results

Post by tommi59 on 21st September 2012, 4:19 pm

5 earth radius planet corot 24 c with density around 1.8 g/cm3 not bad and much denser planet b around 4.0 g/cm3 and another planet nice

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Re: CoRoT Results

Post by Lazarus on 21st September 2012, 8:44 pm

From A&A:

Detection of Neptune-size planetary candidates with CoRoT data: Comparison with the planet occurrence rate derived from Kepler

Seems that the occurrence rate of Neptunes in the CoRoT data disagrees with that from Kepler: the Kepler occurrence rate predicts that CoRoT should have found more Neptunes by now.

Potential implications for false-positive rates in the transit surveys.

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Re: CoRoT Results

Post by pochimax on 23rd September 2012, 3:39 am

They should observe more bright stars. The majority of candidates found by corot are 13 mag or above...and they have a very little telescope in comparison with Kepler.

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Re: CoRoT Results

Post by Sirius_Alpha on 23rd September 2012, 8:10 pm

A paper on arXiv about this very topic.
http://arxiv.org/abs/1209.4815

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Re: CoRoT Results

Post by Lazarus on 15th October 2012, 2:37 pm

Checking that the CoRoT planet transits behave as expected at different wavelengths...

An analysis of CoRoT multicolour photometry of exoplanets
http://arxiv.org/abs/1210.3549

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Re: CoRoT Results

Post by Galzi on 26th October 2012, 11:53 am

An overview of the mission results obtained so far:

http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-381.pdf

The observation program for the possible next 3 years extension:

http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-198-2.pdf

A dedicated search in the Corot database for close-in planets orbiting intermediate-mass stars:

http://www.eso.org/sci/meetings/2012/ESOat50/Posters/Sebastian.pdf

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Re: CoRoT Results

Post by jyril on 17th November 2012, 7:42 am

Looks like after a serious malfunction on its computer, CoRoT may have finished its business...

Nature: Exoplanet hunter nears its end

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Re: CoRoT Results

Post by Edasich on 17th November 2012, 10:54 am

Nuuuu Crying or Very sad

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Re: CoRoT Results

Post by Led_Zep on 17th November 2012, 3:43 pm

bad news...
But :
« ...Malcolm Fridlund, the project scientist from the European Space Agency, says he’s got plenty of data to work with. He’s preparing a paper that will describe five new exoplanets, bringing the mission’s confirmed count to 31. And there are some 200 candidate exoplanets that remain unconfirmed… »

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Re: CoRoT Results

Post by Galzi on 21st November 2012, 12:37 pm

Interesting hints from the Corot Scientific Meeting on 9 October 2012, before the serious fault happened:

http://smsc.cnes.fr/COROT/SC/sc45/Minutes_SC45_V1.pdf

The summer follow-up campaign on LRc07 and LRc08 fields was good, with 4 new planets + one from SRa04 awaiting publication. The CEST team is preparing the announcement of 5 new planets, in 2-3 papers (led resp. by Parviainen (CoRoT 27), Cabrera (CoRoT 28+29), Bordé (CoRoT 30+31)). They are mainly hot Jupiters (~Mjup and P<5d) but 2 are massive ones (P=10d and 3Mjup and P=4d and 10Mjup)
* The work is continuing on SRa01-0770 not confirmed with RV, re-observed in SRa05; though it is not sure it is a cluster member, it could be validated as planet anyway (Aigrain).
* The LAM team is progressing a lot on the validation procedure when RV is not conclusive, with the tool called PASTIS. Publication is on the way, and the analysis of a dozen of promising cases for which we could not conclude yet but have a lot of data. (Diaz)
* Magali is still working on the "mega paper" summarizing all candidates up to LRc08
* A review on CoRoT/exo for the Icarus special issue on exoplanet is foreseen for end of November
* The publications of the reobservation of CoRoT 7 and CoRoT 9 are being prepared, could be issued by the end of the year (Barros, Haywood, Hebrard)-
* CoRoT /exo program was presented this summer at COSPAR (Wuchterl), in Sagan school (Deleuil), in Beijing at IAU (Deleuil) and in Madrid EPSC (Deeg + Cabrera)
* MF mentions that a paper on host stars characterization is in progress with Magali and himself.

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Re: CoRoT Results

Post by Sirius_Alpha on 25th November 2012, 9:16 pm

Secondary eclipses measured for a couple new planets (and maybe a few more).

Secondary eclipses in the CoRoT light curves: A homogeneous search based on Bayesian model selection
http://arxiv.org/abs/1211.5361

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Re: CoRoT Results

Post by Edasich on 26th November 2012, 5:04 am

A couple new planets? Which ones?

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