Publications by Suzanne Aigrain


Erratum: “An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star” (2019, AJ, 158, 165)

The Astronomical Journal American Astronomical Society 159 (2020) 34-34

AW Mayo, VM Rajpaul, LA Buchhave, CD Dressing, A Mortier, L Zeng, CD Fortenbach, S Aigrain, AS Bonomo, AC Cameron, D Charbonneau, A Coffinet, R Cosentino, M Damasso, X Dumusque, AFM Fiorenzano, RD Haywood, DW Latham, M López-Morales, L Malavolta, E Molinari, L Pearce, G Piotto, E Poretti, A Sozzetti


Understanding and mitigating biases when studying inhomogeneous emission spectra with JWST

Monthly Notices of the Royal Astronomical Society Royal Astronomical Society (2020)

J Taylor, V Parmentier, P Irwin, S Aigrain, G Lee, J Krissansen-Totton

Exoplanet emission spectra are often modelled assuming that the hemisphere observed is well represented by a horizontally homogenised atmosphere. However this approximation will likely fail for planets with a large temperature contrast in the James Webb Space Telescope (JWST) era, potentially leading to erroneous interpretations of spectra. We first develop an analytic formulation to quantify the signal-to-noise ratio and wavelength coverage necessary to disentangle temperature inhomogeneities from a hemispherically averaged spectrum. We find that for a given signal-to-noise ratio, observations at shorter wavelengths are better at detecting the presence of inhomogeneities. We then determine why the presence of an inhomogeneous thermal structure can lead to spurious molecular detections when assuming a fully homogenised planet in the retrieval process. Finally, we quantify more precisely the potential biases by modelling a suite of hot Jupiter spectra, varying the spatial contributions of a hot and a cold region, as would be observed by the different instruments of JWST/NIRSpec. We then retrieve the abundances and temperature profiles from the synthetic observations. We find that in most cases, assuming a homogeneous thermal structure when retrieving the atmospheric chemistry leads to biased results, and spurious molecular detection. Explicitly modelling the data using two profiles avoids these biases, and is statistically supported provided the wavelength coverage is wide enough, and crucially also spanning shorter wavelengths. For the high contrast used here, a single profile with a dilution factor performs as well as the two-profile case, with only one additional parameter compared to the 1-D approach.


Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit

Monthly Notices of the Royal Astronomical Society Oxford University Press 494 (2020) 750-763

N Eisner, O Barragan Villanueva, S Aigrain, C Lintott, G Miller, N Zicher, TS Boyajian, C Briceño, EM Bryant, JL Christiansen, AD Feinstein, LM Flor-Torres, M Fridlund, D Gandolfi, J Gilbert, N Guerrero, JM Jenkins, K Jones, M Christensen, A Vanderburg, AR López-Sánchez, C Ziegler, DM Bundy, LD Melanson, I Terentev

We report on the discovery and validation of TOI 813b (TIC 55525572 b), a transiting exoplanet identified by citizen scientists in data from NASA's Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant (USDR_\star=1.94\,R_\odotUSD, USDM_\star=1.32\,M_\odotUSD). It was observed almost continuously by TESS during its first year of operations, during which time four individual transit events were detected. The candidate passed all the standard light curve-based vetting checks, and ground-based follow-up spectroscopy and speckle imaging enabled us to place an upper limit of USD2 M_{Jup}USD (99 % confidence) on the mass of the companion, and to statistically validate its planetary nature. Detailed modelling of the transits yields a period of USD83.8911_{ - 0.0031 } ^ { + 0.0027 }USD days, a planet radius of USD6.71 \pm 0.38$ $R_{\oplus}$, and a semi major axis of $0.423_{ - 0.037 } ^ { + 0.031 }USD AU. The planet's orbital period combined with the evolved nature of the host star places this object in a relatively under-explored region of parameter space. We estimate that TOI-813b induces a reflex motion in its host star with a semi-amplitude of USD\sim6USD msUSD^{-1}USD, making this system a promising target to measure the mass of a relatively long-period transiting planet.


Mon-735: a new low-mass pre-main-sequence eclipsing binary in NGC 2264

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 495 (2020) 1531-1548

E Gillen, LA Hillenbrand, J Stauffer, S Aigrain, L Rebull, AM Cody

<jats:title>ABSTRACT</jats:title> <jats:p>We present Mon-735, a detached double-lined eclipsing binary (EB) member of the ∼3 Myr old NGC 2264 star-forming region, detected by Spitzer. We simultaneously model the Spitzer light curves, follow-up Keck/HIRES radial velocities, and the system’s spectral energy distribution to determine self-consistent masses, radii, and effective temperatures for both stars. We find that Mon-735 comprises two pre-main-sequence M dwarfs with component masses of M = 0.2918 ± 0.0099 and 0.2661 ± 0.0095 M⊙, radii of R = 0.762 ± 0.022 and 0.748 ± 0.023 R⊙, and effective temperatures of Teff = 3260 ± 73 and 3213 ± 73 K. The two stars travel on circular orbits around their common centre of mass in P = 1.9751388 ± 0.0000050 d. We compare our results for Mon-735, along with another EB in NGC 2264 (CoRoT 223992193), to the predictions of five stellar evolution models. These suggest that the lower mass EB system Mon-735 is older than CoRoT 223992193 in the mass–radius diagram (MRD) and, to a lesser extent, in the Hertzsprung–Russell diagram (HRD). The MRD ages of Mon-735 and CoRoT 223992193 are ∼7–9 and 4–6 Myr, respectively, with the two components in each EB system possessing consistent ages.</jats:p>


Pleiades or Not? Resolving the Status of the Lithium-rich M Dwarfs HHJ 339 and HHJ 430

The Astronomical Journal American Astronomical Society 160 (2020) 30-30

J Stauffer, D Barrado, T David, LM Rebull, LA Hillenbrand, EE Mamajek, R Oppenheimer, S Aigrain, H Bouy, J Lillo-Box

Oppenheimer et al. (1997) discovered two M5 dwarfs in the Pleiades with nearly primordial lithium. These stars are not low enough in mass to represent the leading edge of the lithium depletion boundary at Pleiades age (~125 Myr). A possible explanation for the enhanced lithium in these stars is that they are actually not members of the Pleiades but instead are members of a younger moving group seen in projection towards the Pleiades. We have used data from Gaia DR2 to confirm that these two stars, HHJ 339 and HHJ 430, are indeed not members of the Pleiades. Based on their space motions, parallaxes and positions in a Gaia-based CMD, it is probable that these two stars are about 40 parsecs foreground to the Pleiades and have ages of ~25 Myr. Kinematically they are best matched to the 32 Ori moving group.


A robust, template-free approach to precise radial velocity extraction

Monthly Notices of the Royal Astronomical Society Oxford University Press 492 (2020) 3960-3983

VM Rajpaul, S Aigrain, LA Buchhave

Doppler spectroscopy is a powerful tool for discovering and characterizing exoplanets. For decades, the standard approach to extracting radial velocities (RVs) has been to cross-correlate observed spectra with a weighted template mask. While still widely used, this approach is known to suffer numerous drawbacks, and so in recent years increasing attention has been paid to developing new and improved ways of extracting RVs. In this proof-of-concept paper, we present a simple yet powerful approach to RV extraction. We use Gaussian processes to model and align all pairs of spectra with each other; we combine the pairwise RVs thus obtained to produce accurate differential stellar RVs, without constructing any template. Doing this on a highly localized basis enables a data-driven approach to identifying and mitigating spectral contamination, even without the input of any prior astrophysical knowledge. We show that a crude implementation of this method applied to an inactive standard star yields RVs with comparable precision to and significantly lower rms variation than RVs from industry-standard pipelines. Though amenable to numerous improvements, even in its basic form presented here our method could facilitate the study of smaller planets around a wider variety of stars than has previously been possible.


Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Oxford University Press (OUP) 490 (2019) 698-708

D Kubyshkina, D Gandolfi, J Livingston, MCV Fridlund, L Fossati, J Korth, H Parviainen, L Malavolta, E Palle, HJ Deeg, G Nowak, VM Rajpaul, N Zicher, G Antoniciello, N Narita, S Albrecht, LR Bedin, J Cabrera, WD Cochran, J de Leon, P Eigmueller, A Fukui, N Kusakabe, M Libralato, P Montanes-Rodriguez

© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6 ± 3.0 m s−1, which matches the transit ephemeris, and translates to a planet mass of 21.8 ± 6.2 M. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, 2.04+−006661 g cm−3, implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of 1011–1012 g s−1 due to the high level of radiation it receives from its host star.


An 11 Earth-mass, long-period Sub-Neptune orbiting a Sun-like star

Astronomical Journal American Astronomical Society 158 (2019) 165-165

AW Mayo, VM Rajpaul, LA Buchhave, CD Dressing, CD Fortenbach, S Aigrain, AC Cameron, D Charbonneau, A Coffinet, R Cosentino, M Damasso, X Dumusque, RD Haywood, DW Latham, M López-Morales, G Micela, E Molinari, L Pearce, F Pepe, D Phillips, E Poretti, G Piotto, K Rice, A Sozzetti, S Udry

Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long-period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such planets. In this paper we report the mass estimation and characterization of the long-period exoplanet Kepler-538b. This planet orbits a Sun-like star (V = 11.27) with = - M + 0.892 0.035 0.051* Me and R =* - + 0.8717 0.0061 0.0064 Re. Kepler-538b is a - + 2.215 0.034 0.040 R⊕ sub-Neptune with a period of P = 81.73778 ± 0.00013 days. It is the only known planet in the system. We collected radial velocity (RV) observations with the High Resolution Echelle Spectrometer (HIRES) on Keck I and High Accuracy Radial velocity Planet Searcher in North hemisphere (HARPS-N) on the Telescopio Nazionale Galileo (TNG). We characterized stellar activity by a Gaussian process with a quasi-periodic kernel applied to our RV and cross-correlation function FWHM observations. By simultaneously modeling Kepler photometry, RV, and FWHM observations, we found a semi-amplitude of = -+ K 1.68 0.38 0.39 m s−1 and a planet mass of = - M + p 10.6 2.4 2.5 M⊕. Kepler-538b is the smallest planet beyond P = 50 days with an RV mass measurement. The planet likely consists of a significant fraction of ices (dominated by water ice), in addition to rocks/metals, and a small amount of gas. Sophisticated modeling techniques such as those used in this paper, combined with future spectrographs with ultra high-precision and stability will be vital for yielding more mass measurements in this poorly understood exoplanet regime. This in turn will improve our understanding of the relationship between planet composition and insolation flux and how the rocky to gaseous transition depends on planetary equilibrium temperature.


A ghost in the toast: TESS background light produces a false “transit” across τ Ceti

Research Notes of the AAS American Astronomical Society 3 (2019) 145-

N Eisner, B Pope, S Aigrain, O Barragan Villanueva, TR White, CX Huang, C Lintott, A Volkov


Constraining the properties of HD 206893 B. A combination of radial velocity, direct imaging, and astrometry data

Astronomy and Astrophysics EDP Sciences 627 (2019) L9

A Grandjean, A-M Lagrange, H Beust, L Rodet, J Milli, P Rubini, C Babusiaux, N Meunier, P Delorme, S Aigrain, N Zicher, M Bonnefoy, BA Biller, J-L Baudino, M Bonavita, A Boccaletti, A Cheetham, JH Girard, J Hagelberg, M Janson, J Lannier, C Lazzoni, R Ligi, A-L Maire, C Perrot

<p><em>Context.</em> High contrast imaging enables the determination of orbital parameters for substellar companions (planets, brown dwarfs) from the observed relative astrometry and the estimation of model and age-dependent masses from their observed magnitudes or spectra. Combining astrometric positions with radial velocity gives direct constraints on the orbit and on the dynamical masses of companions. A brown dwarf was discovered with the VLT/SPHERE instrument at the Very Large Telescope (VLT) in 2017, which orbits at ∼11 au around HD 206893. Its mass was estimated between 12 and 50 <em>M</em><sub>J</sub> from evolutionary models and its photometry. However, given the significant uncertainty on the age of the system and the peculiar spectrophotometric properties of the companion, this mass is not well constrained.</p> <p><em>Aims</em>. We aim at constraining the orbit and dynamical mass of HD 206893 B.</p> <p><em>Methods</em>. We combined radial velocity data obtained with HARPS spectra and astrometric data obtained with the high contrast imaging VLT/SPHERE and VLT/NaCo instruments, with a time baseline less than three years. We then combined those data with astrometry data obtained by HIPPARCOS and <em>Gaia</em>with a time baseline of 24 yr. We used a Markov chain Monte Carlo approach to estimate the orbital parameters and dynamical mass of the brown dwarf from those data.</p> <p><em>Results.</em> We infer a period between 21 and 33 yr and an inclination in the range 20−41° from pole-on from HD 206893 B relative astrometry. The RV data show a significant RV drift over 1.6 yr. We show that HD 206893 B cannot be the source of this observed RV drift as it would lead to a dynamical mass inconsistent with its photometry and spectra and with HIPPARCOS and <em>Gaia</em> data. An additional inner (semimajor axis in the range 1.4–2.6 au) and massive (∼15 <em>M</em><sub>J</sub>) companion is needed to explain the RV drift, which is compatible with the available astrometric data of the star, as well as with the VLT/SPHERE and VLT/NaCo nondetection.</p>


Stellar activity and rotation of the planet host Kepler-17 from long-term space-borne photometry

Astronomy and Astrophysics EDP Sciences 626 (2019) A38

AF Lanza, Y Netto, AS Bonomo, H Parviainen, A Valio, S Aigrain

<p><strong>Context.</strong> The study of young Sun-like stars is fundamental to understanding the magnetic activity and rotational evolution of the Sun. Space-borne photometry by the Kepler telescope provides unprecedented datasets to investigate these phenomena in Sun-like stars.</p> <p><strong>Aims.</strong> We present a new analysis of the entire Kepler photometric time series of the moderately young Sun-like star Kepler-17 accompanied by a transiting hot Jupiter.</p> <p><strong>Methods.</strong> We applied a maximum-entropy spot model to the long-cadence out-of-transit photometry of the target to derive maps of the starspot filling factor versus the longitude and the time. These maps are compared to the spots occulted during transits to validate our reconstruction and derive information on the latitudes of the starspots.</p> <p><strong>Results.</strong> We find two main active longitudes on the photosphere of Kepler-17, one of which has a lifetime of at least ∼1400 days although with a varying level of activity. The latitudinal differential rotation is of solar type, that is, with the equator rotating faster than the poles. We estimate a minimum relative amplitude ΔΩ/Ω between ∼0.08 ± 0.05 and 0.14 ± 0.05, our determination being affected by the finite lifetime of individual starspots and depending on the adopted spot model parameters. We find marginal evidence of a short-term intermittent activity cycle of ∼48 days and an indication of a longer cycle of 400−600 days characterized by an equatorward migration of the mean latitude of the spots as in the Sun. The rotation of Kepler-17 is likely to be significantly affected by the tides raised by its massive close-by planet.</p> <p><strong>Conclusions.</strong> We confirm the reliability of maximum-entropy spot models to map starspots in young active stars and characterize the activity and differential rotation of this young Sun-like planetary host.</p>


Constraining the properties of HD 206893 B A combination of radial velocity, direct imaging, and astrometry data (vol 627, L9, 2019)

ASTRONOMY & ASTROPHYSICS 629 (2019) ARTN C1

A Grandjean, A-M Lagrange, H Beust, L Rodet, J Milli, P Rubini, C Babusiaux, N Meunier, P Delorme, S Aigrain, M Bonnefoy, J-L Baudino, M Bonavita, A Boccaletti, A Cheetham, J Hagelberg, M Janson, J Lannier, C Lazzoni, R Ligi, A-L Maire, D Mesa, C Perrot, D Rouan, A Zurlo

© A. Grandjean et al. 2019. The distance d was missing in the denominator of the first equation of Appendix D.2. The corrected equation is: (Formula Presented).


An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star

ASTRONOMICAL JOURNAL 158 (2019) ARTN 165

AW Mayo, VM Rajpaul, LA Buchhave, CD Dressing, A Mortier, L Zeng, CD Fortenbach, S Aigrain, AS Bonomo, AC Cameron, D Charbonneau, A Coffinet, R Cosentino, M Damasso, X Dumusque, AF Martinez Fiorenzano, RD Haywood, DW Latham, M Lopez-Morales, L Malavolta, G Micela, E Molinari, L Pearce, F Pepe, D Phillips, G Piotto, E Poretti, K Rice, A Sozzetti, S Udry


The K2 Bright Star Survey. I. Methodology and Data Release

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES American Astronomical Society 245 (2019) ARTN 8

BJS Pope, TR White, WM Farr, J Yu, M Greklek-McKeon, D Huber, C Aerts, S Aigrain, TR Bedding, T Boyajian, OL Creevey, DW Hogg

While the Kepler Mission was designed to look at tens of thousands of faint stars (V &gt; 12), brighter stars that saturated the detector are important because they can be and have been observed very accurately by other instruments. By analyzing the unsaturated scattered-light `halo' around these stars, we have retrieved precise light curves of most of the brightest stars in K2 fields from Campaign~4 onwards. The halo method does not depend on the detailed cause and form of systematics, and we show that it is effective at extracting light curves from both normal and saturated stars. The key methodology is to optimize the weights of a linear combination of pixel time series with respect to an objective function. We test a range of such objective functions, finding that lagged Total Variation, a generalization of Total Variation, performs well on both saturated and unsaturated K2 targets. Applying this to the bright stars across the K2 Campaigns reveals stellar variability ubiquitously, including effects of stellar pulsation, rotation, and binarity. We describe our pipeline and present a catalogue of the 161 bright stars, with classifications of their variability, asteroseismic parameters for red giants with well-measured solar-like oscillations, and remarks on interesting objects. These light curves are publicly available as a High Level Science Product from the Mikulski Archive for Space Telescopes (MAST).


The K2 Bright Star Survey. I. Methodology and data release

Astrophysical Journal Supplement American Astronomical Society 245 (2019) 8

BJS Pope, TR White, WM Farr, J Yu, M Greklek-McKeon, D Huber, C Aerts, S Aigrain, TR Bedding, T Boyajian, OL Creevey, DW Hogg

While the Kepler mission was designed to look at tens of thousands of faint stars (V gsim 12), brighter stars that saturated the detector are important because they can be and have been observed very accurately by other instruments. By analyzing the unsaturated scattered-light "halo" around these stars, we retrieved precise light curves of most of the brightest stars in K2 fields from Campaign 4 onward. The halo method does not depend on the detailed cause and form of systematics, and we show that it is effective at extracting light curves from both normal and saturated stars. The key methodology is to optimize the weights of a linear combination of pixel time series with respect to an objective function. We test a range of such objective functions, finding that lagged Total Variation, a generalization of Total Variation, performs well on both saturated and unsaturated K2 targets. Applying this to the bright stars across the K2 Campaigns reveals stellar variability ubiquitously, including effects of stellar pulsation, rotation, and binarity. We describe our pipeline and present a catalog of the 161 bright stars, with classifications of their variability, asteroseismic parameters for red giants with well-measured solar-like oscillations, and remarks on interesting objects. These light curves are publicly available as a High Level Science Product from the Mikulski Archive for Space Telescopes (footnote 17).


The K2 M67 Study: A Curiously Young Star in an Eclipsing Binary in an Old Open Cluster

ASTRONOMICAL JOURNAL 155 (2018) ARTN 152

EL Sandquist, RD Mathieu, SN Quinn, ML Pollack, DW Latham, TM Brown, R Esselstein, S Aigrain, H Parviainen, A Vanderburg, D Stello, G Somers, MH Pinsonneault, J Tayar, JA Orosz, LR Bedin, M Libralato, L Malavolta, D Nardiello


A Universal Spin-Mass Relation for Brown Dwarfs and Planets

Astrophysical Journal 859 (2018)

A Scholz, K Moore, R Jayawardhana, S Aigrain, D Peterson, B Stelzer

© 2018. The American Astronomical Society. All rights reserved. While brown dwarfs show similarities to stars early in their lives, their spin evolutions are much more akin to those of planets. We have used light curves from the K2 mission to measure new rotation periods for 18 young brown dwarfs in the Taurus star-forming region. Our sample spans masses from 0.02 to 0.08 Moand has been characterized extensively in the past. To search for periods, we utilize three different methods (autocorrelation, periodogram, Gaussian processes). The median period for brown dwarfs with disks is twice as long as for those without (3.1 versus 1.6 days), a signature of rotational braking by the disk, albeit with small numbers. With an overall median period of 1.9 days, brown dwarfs in Taurus rotate slower than their counterparts in somewhat older (3-10 Myr) star-forming regions, consistent with spin-up of the latter due to contraction and angular momentum conservation, a clear sign that disk braking overall is inefficient and/or temporary in this mass domain. We confirm the presence of a linear increase of the typical rotation period as a function of mass in the substellar regime. The rotational velocities, when calculated forward to the age of the solar system, assuming angular momentum conservation, fit the known spin-mass relation for solar system planets and extra-solar planetary-mass objects. This spin-mass trend holds over six orders of magnitude in mass, including objects from several different formation paths. Our result implies that brown dwarfs by and large retain their primordial angular momentum through the first few Myr of their evolution.


The GTC exoplanet transit spectroscopy survey VIII. Flat transmission spectrum for the warm gas giant WASP-80b

ASTRONOMY & ASTROPHYSICS 609 (2018) ARTN A33

H Parviainen, E Palle, G Chen, L Nortmann, F Murgas, G Nowak, S Aigrain, A Booth, M Abazorius, N Iro


The K2 M67 Study: Establishing the Limits of Stellar Rotation Period Measurements in M67 with K2 Campaign 5 Data

ASTROPHYSICAL JOURNAL 859 (2018) ARTN 167

R Esselstein, S Aigrain, A Vanderburg, JC Smith, S Meibom, J Van Saders, R Mathieu


Planets, candidates, and binaries from the CoRoT/Exoplanet programme: the CoRoT transit catalogue

Astronomy and Astrophysics Springer Verlag (2018)

M Deleuil, S Aigrain, C Moutou, J Cabrera, F Bouchy, HJ Deeg, J-M Almenara, G Hébrard, A Santerne, R Alonso, AS Bonomo, P Bordé, S Csizmadia, A Erikson, M Fridlund, D Gandolfi, E Guenther, T Guillot, P Guterman, S Grziwa, A Hatzes, A Léger, T Mazeh, A Ofir, M Ollivier, M Pätzold, H Parviainen, H Rauer, D Rouan, J Schneider, R Titz-Weider, B Tingley, J Weingrill

We provide the catalogue of all transit-like features, including false alarms, detected by the CoRoT exoplanet teams in the 177 454 light curves of the mission. All these detections have been re-analysed with the same softwares so that to ensure their homogeneous analysis. Although the vetting process involves some human evaluation, it also involves a simple binary flag system over basic tests: detection significance, presence of a secondary, difference between odd and even depths, colour dependence, V-shape transit, and duration of the transit. We also gathered the information from the large accompanying ground-based programme carried out on the planet candidates and checked how useful the flag system could have been at the vetting stage of the candidates. In total, we identified and separated 824 false alarms of various kind, 2269 eclipsing binaries among which 616 are contact binaries and 1653 are detached ones, 37 planets and brown dwarfs, and 557 planet candidates. For the planet candidates, the catalogue gives not only their transit parameters but also the products of their light curve modelling, together with a summary of the outcome of follow-up observations when carried out and their current status. Among the planet candidates whose nature remains unresolved, we estimate that 8 +/- 3 planets are still to be identified. We derived planet and brown dwarf occurrences and confirm disagreements with Kepler estimates: small-size planets with orbital period less than ten days are underabundant by a factor of three in the CoRoT fields whereas giant planets are overabundant by a factor of two. These preliminary results would however deserve further investigations using the recently released CoRoT light curves that are corrected of the various instrumental effects and a homogeneous analysis of the stellar populations observed by the two missions.

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