CoRoT Results

exofever wrote:

I wonder what instrument they have used for radial velocity confirmation. I searched the ESO archives but couldn't find any observations related to these objects.

I'm fairly sure the CoRoT planets are confirmed through HARPS. I'm not 100% certain though.

More spectrographs are involved: CORALIE, SOPHIE, FLAMES, HARPS ... at different steps of the follow up. See the PPT below (I googled it, not hidden ).

http://smsc.cnes.fr/COROT/contrib_cw8/Doppler_follow_up.ppt



Cheers

A nice presentation. Mentions Corot-8b and -9b but no details. Also description of Plato mission.

http://www.rssd.esa.int/SD/ESACFACULTY/docs/seminars/251109_Carpano.pdf

Public. Just Google "Corot 9b" (first link).

exoplanet wrote:

More spectrographs are involved: CORALIE, SOPHIE, FLAMES, HARPS ... at different steps of the follow up. See the PPT below (I googled it, not hidden ).

http://smsc.cnes.fr/COROT/contrib_cw8/Doppler_follow_up.ppt

There is else observations on telescope Keck-HIRES

http://nexsci.caltech.edu/missions/KeckSolicitation/proposal-current.shtml

Quote :

2010A</A>

M. Endl

McDonald Observatory/Univ. of Texas Austin

Key

Mass Determination of High Priority CoRoT Planet Candidates III

x

HIRESr

Quote :

2009B</A>

M. Endl

McDonald Observatory/Univ. of Texas Austin

Key

Mass Determination of High Priority CoRoT Planet Candidates II

x

HIRESr

Quote :

2009A

M. Endl

McDonald Obs.

Key

Mass Determination of High Priority CoRoT Planet Candidates

x

HIRESr

http://www2.keck.hawaii.edu/observing/schedule/index.php
Endl users HIRES 29-30.06.2009, 04.12.2009, 24-28.01.2010, 18-20.06.2010.

In general 11 observant nights on 10-metre telescope.

News from the CoRoT Space Mission
http://arxiv.org/abs/0912.4655

Abstract wrote:

The up to 150 day uninterrupted high-precision photometry of about 100000 stars - provided so far by the exoplanet channel of the CoRoT space telescope - gave a new perspective on the planet population of our galactic neighbourhood. The seven planets with very accurate parameters widen the range of known planet properties in almost any respect. Giant planets have been detected at low metallicity, rapidly rotating and active, spotted stars. CoRoT-3 populated the brown dwarf desert and closed the gap of measured physical properties between standard giant planets and very low mass stars. CoRoT extended the known range of planet masses down to 5 Earth masses and up to 21 Jupiter masses, the radii to less than 2 Earth radii and up to the most inflated hot Jupiter found so far, and the periods of planets discovered by transits to 9 days. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planet-host-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that terrestrial planets with a density close to Earth exist outside the Solar System. The detection of the secondary transit of CoRoT-1 at the $10^{-5}$-level and the very clear detection of the 1.7 Earth radii of CoRoT-7b at $3.5 10^{-4}$ relative flux are promising evidence of CoRoT being able to detect even smaller, Earth sized planets.

there is still more interest news that come from COROT probabily soon ....

http://arxiv.org/abs/0912.4655

on the end of the this paper, that catch my attention:


The presentation of the major results in this overview
is by far not complete – e.g. we did not speak about time
transit variations (TTV) – which have also been detected
in some of the data and may be caused by additional planets
in the system. Only the results of the confirmed planets
have been presented5, but the signals of manymore planets
seem to be still in our data like the ones of planets around
double stars. But they can be confirmed only after difficult
and long analysis combined with observations from
the ground.

circumbinary planet probabily come soon from kepler and corot mission

Ah, so yet more evidence that the astronomical community's ability to detect transit-like events is far outstripping the ability to confirm whether they are genuinely caused by planets.

Lazarus wrote:

Ah, so yet more evidence that the astronomical community's ability to detect transit-like events is far outstripping the ability to confirm whether they are genuinely caused by planets.

the astronomical community,they prove already that are capable to detect and confirm planets around binary stars by timing by telescope on the ground,and corot a much more precisely,maybe that take time... but it's not impossible not for COROT,and not for the ground telescope.

Problem is that detecting something that looks like a transit is not enough - the lesson from the various transit surveys is that genuine planetary transits are much rarer than false positives. On its own, CoRoT cannot confirm the effect on the lightcurve is a planet.

While circumbinary planets have been detected from the ground, the detection method used is eclipse timing, which is sensitive to long-period planets. Transits of circumbinary planets would be from planets orbiting close to the stars. Maybe Maciej Konacki's technique for extracting precision radial velocities from binary stars will help.

Lazarus wrote:

While circumbinary planets have been detected from the ground, the detection method used is eclipse timing, which is sensitive to long-period planets. Transits of circumbinary planets would be from planets orbiting close to the stars. Maybe Maciej Konacki's technique for extracting precision radial velocities from binary stars will help.

that is point, the corot mission could detect a circumbinary planet by use the method of eclipse timing,becuase corot and kepler it's very photometric precise for eclipse binary star timing that can be confirm by the own telescope.

the same is valid for exomoons,when the planet transit the star we can measure the transit timing then calculate the exomoon sin mass

i read a scientific paper about it if i found i post here

but the confimation take while of course

That assumes the transiting planet has a detectable moon, which may be a fairly rare occurrence. Most of the transiting exoplanets will not have any detectable moons, and thus no way to determine the mass through the light curve alone.

Sirius_Alpha wrote:

which may be a fairly rare occurrence..

where are take that conclusion that exomoons is rare around gas giant planet?

only our solar system planets have more that 150 moons, jupiter 64 moons wich 4 are big one,ever the scientist don't know how many is out there on our galaxy

that is wikipedia that talk about ways to detect exomoons.

http://en.wikipedia.org/wiki/Extrasolar_moon

and that is the recent discursion about exomoons on centauri dreams

http://www.centauri-dreams.org/?p=10723

Characterizing Habitable Exo-Moons

http://arxiv.org/abs/0912.3484

Pathways Towards Habitable Moons... that could be detect by kepler as the paper say

http://arxiv.org/abs/0911.5170

Sirius_Alpha wrote:

That assumes the transiting planet has a detectable moon, which may be a fairly rare occurrence. Most of the transiting exoplanets will not have any detectable moons, and thus no way to determine the mass through the light curve alone.

kepler should detect gas giant on the habitable zone,then this gas giant could have your own moons like jupiter have

like the ilustration of the hypothetical exomoon around HD28185b on this site

this detail call my attention about exomoon on the wikipedia:

http://en.wikipedia.org/wiki/Extrasolar_moon

Transit timing effects
In 2009, University College London-based astronomer David Kipping published a paper[4][5] outlining how by combining multiple observations of variations in the time of mid-transit (TTV, caused by the planet leading or trailing the planet-moon system's center of gravity when the moon and planet are oriented roughly perpendicular to the line of site) with variations of the transit duration (TDV, caused by the planet moving along the direction path of transit relative to the planet-moon system's center of gravity when the moon-planet axis lies roughly along the line of site) a unique exomoon signature is produced. Furthermore, the work demonstrated how both the mass of the exomoon and its orbital distance from the planet could be determined using the two effects.

In a later study, the author and two colleagues have concluded that habitable zone exomoons could be detected by the Kepler space telescope[6] using the TTV and TDV effects.

this is the paper:

On the detectability of habitable exomoons with Kepler-class photometry

http://xxx.lanl.gov/abs/0907.3909

there not scientific paper that said that is rare detect exomoons by Transit timing effects,exomoons should be common like our solar system, so it's possibledetect around gas giant transit planets by Kepler or Corot.

in hot jupiter transit maybe exomoons it's rare,jupiter in habitable zone and out i don't think so

this paper it's about:

Timing Detection of Eclipsing Binary Planets and Transiting Extrasolar Moons

http://arxiv.org/abs/astro-ph/0306087

a little old paper, but still valid and useful for the corot and kepler scientists...

conclusion:

we can detect and confirm exomoons,mass and distance, ever in special condition study the exomoons atmophere like said on recent scientifics paper.

Same for exoplanet around eclipsing binary system,we can confirm they mass and distance with the current tecnology

Daniel wrote:

where are take that conclusion that exomoons is rare around gas giant planet?

The probability that a planet will transit the star is greater if the planet is near the star. This is why the overwhelming majority of the transiting extrasolar planets to date are in very short period orbits. The geometric probability for any given planet with a random orbit to transit is d / 2a, where d is the stellar diameter, and a is the distance the planet is from the star. You can see that short-period planets are more likely to transit than long-period planets.

The region of space around a planet in which the planet is the dominant gravitational influence is called the "gravitational hill sphere" (or just "hill sphere"). As the distance from a star increases, the gravitational attraction between the star and the planet decreases. This allows the planet to have more gravitational influence on the local space than the star. As such, Jupiter has a larger hill sphere where it is now than it would be if it were at Mercury's semi-major axis. Similarly, Neptune has a larger hill sphere than Jupiter, simply because it is farther from the sun.

The radius of the hill sphere of a planet can be expressed by

r = a(1 - e) * (m / 3M)^1/3

http://en.wikipedia.org/wiki/Hill_sphere

Where a is the semi-major axis of the orbit, m is the mass of the secondary (the planet in this case), and M is the mass of the primary (the star in this case). The hill sphere of a planet is greatly reduced as the planet approaches the star. Furthermore, orbits within the hill sphere are usually only truly stable in the long term if they don't exceed ~1/3 of the hill sphere radius. A moon just within the hill sphere is still subject to non-negligible gravitational influence from the star, and the orbit will be unstable.

For a Jovian-mass planet around a Solar-mass star in a typical a = 0.03 AU orbit, the hill sphere of the planet will be about 0.002 AU in radius. Stable orbits can be expected then to be at semi-major axes no more than (1/3) * 0.002 AU =~ 100,000 km. Minus the radius of the planet, 70,000 for a Jovian-radius planet, gives you a maximum moon altitude of 30,000 km.

The Roche limit is the distance from a planet that, when a satellite gets sufficiently close, will tidally disrupt. It's dependent on several factors, but for a rigid spherical satellite, it may be expressed as

d = R(2 * ρ_M/ρ_m)^1/3.

http://en.wikipedia.org/wiki/Roche_limit

Where d is the distance from the planet, R is the radius of the primary, ρ_M is the density of the primary (in this case, the planet), ρ_m is the density of the secondary (in this case, the moon).

The Roche limit is the reason why all the moons very near our gas giant planets are small pebbles. If they were larger, they would be tidally disrupted. Large moons would have to be farther out to avoid tidal disruption.

To recap:
Planets closer to the star are more likely to transit.
Planets closer to the star have smaller hill spheres, leaving less room for moons.
Moons can't orbit too close to their planet to avoid being pulled away from the planet because they would be tidally disrupted. So the presence of detectable moons around hot Jupiters does not seem feasible.

Another issue is how they can form in the first place and stay around the gas giant through the course of its migration inward. As the planet migrates in, the hill radius shrinks, the moon walks away. The moon would have to form close to the planet (perhaps just outside the Roche limit), and survive long enough for the planet to migrate inward. How moons can form at such altitudes is of similar difficulty as gas giants forming in short period orbits. There's not much matter to make something out of.

Daniel wrote:

only our solar system planets have more that 150 moons, jupiter 64 moons wich 4 are big one,

If Jupiter were orbiting the sun in a hot Jupiter orbit, all of those moons would be lost, except for perhaps the four inner pebbles (Metis, Adrastea, Amalthea, Thebe). None of these are large enough to be detected in CoRoT/Kepler photometry.

For a gas giant to have a detectable exomoon, it must orbit the star far enough away so that the planet can retain a firm hold on the moon. This means that those short period planets aren't going to be very good targets. When CoRoT/Kepler start detecting gas planets in intermediate or long period orbits, then I would expect moons to begin to be discovered. Since these planets are more rare than short period transiting planets (because of the geometry involved), so will the detection of exomoons.

I wasn't saying that exomoons themselves are rare, but rather, that exomoons detectable through transits would be much more rare than transiting planets.

Sirius_Alpha i agree with you in all that you said,

and yes when we talk about transit planet it's more easy find hot jupiter that long period gas giant transit,and i know hot jupiters are unlikely to have moons...

but in Kepler,was design speciality to detect long period planets transit,its because of that kepler look planet transit for 4 years on same area of sky try to detect long period planet on transit, and of that was planets that i was talk about,and not hot jupiters

scientist say that hot jupiter are only 5% of the gas giants in our galaxy,they are more easy to detect because they proximity of the star,so the probability of detect transit it's much more bigger that detect of long period gas giant on the habitable zone,but still not impossible,

red dwarf and orange dwarf on this case its much more better to detect this exomoons because of close habitable zone,however as you said not so close for not diruspt the exomoon orbit,

a good example of gas giant on the habitable zone of red dwarf it's Gliese 876 that have 2 gas giant on habitable zone that could have habitable exomoon because they far enough for each other and for the star

if kepler found planet like gliese 876 around other red dwarf and with exomoons on the habitable zone,should be a great discovery of all

unfortunately the planets of Gliese876 don't transit the star

Daniel wrote:

that is point, the corot mission could detect a circumbinary planet by use the method of eclipse timing,becuase corot and kepler it's very photometric precise for eclipse binary star timing that can be confirm by the own telescope.

Assuming total binary mass of 2 solar masses, planet mass of 1 Jupiter mass, orbital period 50 days (to match the length of time CoRoT observes the field) and an edge-on planetary orbit, the light travel time fluctuation has a semi-amplitude of about 80 milliseconds. This is going to be very challenging to detect - I recall seeing a paper which claimed CoRoT could not detect circumbinary planets by eclipse timing because for planets with orbital periods which are comparable to the observation time, the light travel time variation is too small to detect.

Lazarus wrote:

Daniel wrote:

that is point, the corot mission could detect a circumbinary planet by use the method of eclipse timing,becuase corot and kepler it's very photometric precise for eclipse binary star timing that can be confirm by the own telescope.

Assuming total binary mass of 2 solar masses, planet mass of 1 Jupiter mass, orbital period 50 days (to match the length of time CoRoT observes the field) and an edge-on planetary orbit, the light travel time fluctuation has a semi-amplitude of about 80 milliseconds. This is going to be very challenging to detect - I recall seeing a paper which claimed CoRoT could not detect circumbinary planets by eclipse timing because for planets with orbital periods which are comparable to the observation time, the light travel time variation is too small to detect.

look what i found about detection of circumbinary planet by Kepler

http://www.seti.org/doyle

look like the kepler could indeed detect such planets

Projects


Detection of Extrasolar Planets Around Eclipsing Binaries in the Kepler Field


NNX08AR15G

About 350 eclipsing binary stars may be found in the NASA Kepler Mission field of view (FOV). We have developed two methods for the discovery of planets around eclipsing binaries -- a matching filter to look at quasi-periodic transit features indicative of a planet in transit across the two moving stars in the background, and a second method using timing of the stellar eclipse minima themselves to see if the stars are being offset by giant planets farther out around a binary-planet barycenter. This last method does not require planetary orbits to be in the line-of-sight orbital plane, and non-detections mean that circum-binary planets of a certain minimum mass are not present. One must know the spectral type and luminosity class of the stars for a determination of the size of the planets (transiting) or their projected mass (eclipsing timing). We will use ground-based Stromvil photometry to spectrally classify each eclipsing binary star system, following this with the application of the Wilson-Devinny (WD) eclipsing binary code to determine the exact parameters of the star systems. We have been guaranteed observing time on the 0.9-meter Crossley telescope at Lick Observatory for these observations. We will then apply a well tested matching filter program correlating light curves of the photometric data with generated models of planetary orbits and sizes in order to detect close-in transiting planets at a quantifiable confidence limit. Over a long term we shall then apply the WD code to see if any changes in binary eclipse epochs have shifted in a periodic way, indicative of larger-orbit circum-binary planets. We estimate that hundreds of additional planets may be discovered in the Kepler FOV in this way and that such circum-binary planets will be of significant interest to our understanding of planet formation processes in close binary star systems.

the scientist Laurance Doyle He is presently a Participating Scientist on the NASA Kepler Mission Science Team with responsibilitiy for detection of extrasolar planets around eclipsing binary systems

http://www.kepler.nasa.gov/Mission/team/lauranceDoyle/

i think that the same is valid for Corot i read i science paper about such detection

http://www.iac.es/galeria/hdeeg/pubs2002/BioAstro02_submitycorr.pdf