- ID:
- ivo://CDS.VizieR/J/A+A/533/A4
- Title:
- CoRoT photometry of three O-type stars
- Short Name:
- J/A+A/533/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detection of pulsational frequencies in stellar photometry is required as input for asteroseismological modelling. The second short run (SRa02) of the CoRoT mission has provided photometric data of unprecedented quality and time-coverage for a number of O-type stars. We analyse the CoRoT data corresponding to three hot O-type stars, describing the properties of their light curves and we search for pulsational frequencies, which we then compare to theoretical model predictions. We determine the amplitude spectrum of the data, using the Lomb-Scargle and a multifrequency HMM-like technique. Frequencies are extracted by prewhitening, and their significance is evaluated under the assumption that the light curve is dominated by red noise. We search for harmonics, linear combinations and regular spacings among these frequencies. We use simulations with the same time sampling as the data as a powerful tool to judge the significance of our results. From the theoretical point of view, we use the MAD non-adiabatic pulsation code to determine the expected frequencies of excited modes. A substantial number of frequencies is listed, but none can be convincingly identified as being connected to pulsations. The amplitude spectrum is dominated by red noise. Theoretical modelling shows that all three O-type stars can have excited modes but the relation between the theoretical frequencies and the observed spectrum is not obvious. The dominant red noise component in the hot O-type stars studied here clearly points to a different origin than the pulsations seen in cooler O stars. The physical cause of this red noise is unclear, but we speculate on the possibility of sub-surface convection, granulation, or stellar wind inhomogeneities being responsible.
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- ID:
- ivo://CDS.VizieR/J/A+A/597/A55
- Title:
- Corot photometry of TYC 455-791-1
- Short Name:
- J/A+A/597/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery and analysis of very narrow transits in the eccentric spectroscopic binary TYC 455-791-1=HSS 348 (IC 4756). We obtained high-precision CoRoT photometry over two long runs and multi-epoch high-resolution echelle spectroscopy and imaging with STELLA. Standard radial-velocity extraction, spectrum synthesis, Fourier analysis, and light-curve inversions are applied to the data. HSS 348 is found to be an eccentric (e=0.18) double-lined spectroscopic binary with a period of 12.47 d in which at least the primary component is a peculiar B star of the HgMn class. The orbital elements are such that the system undergoes a grazing eclipse with the primary in front but no secondary eclipse. The out-of-eclipse light variations show four nearly equidistant but unequal minima stable in shape and amplitude throughout our observations. Their individual photometric periods are all harmonics of the same fundamental period which happens to agree with the transit period to within the errors. We interpret the fundamental period to be the rotation period of at least one if not both stars due to surface inhomogeneities. Due to the non-zero eccentricity of the orbit the two components are rotating sub-synchronously. It appears that HSS 348 is not a member of the IC 4756 cluster but a background B8+B8.5 binary system. Its sharp eclipses every 12.47 days just mimic a small-body transit but are in reality the grazing eclipses of a B-star binary and thus a classical false positive. The system seems to be pre-main sequence with the primary possibly just arrived on the ZAMS. The light curve with four unequal minima can be explained with four cool spots of different size equidistantly positioned in longitude. Our data do not allow to uniquely assign the spots to either of the two stars.
- ID:
- ivo://CDS.VizieR/J/A+A/506/303
- Title:
- CoRoT-7 radial velocities
- Short Name:
- J/A+A/506/303
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on an intensive observational campaign carried out with HARPS at the 3.6m telescope at La Silla on the star CoRoT-7. Additional simultaneous photometric measurements carried out with the Euler Swiss telescope have demonstrated that the observed radial velocity variations are dominated by rotational modulation from cool spots on the stellar surface. Several approaches were used to extract the radial velocity signal of the planet(s) from the stellar activity signal.
- ID:
- ivo://CDS.VizieR/J/A+A/603/A43
- Title:
- CoRoT-9 radial velocity curve
- Short Name:
- J/A+A/603/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CoRoT-9b is one of the rare long-period (P=95.3days) transiting giant planets with a measured mass known to date. We present a new analysis of the CoRoT-9 system based on five years of radial-velocity (RV) monitoring with HARPS and three new space-based transits observed with CoRoT and Spitzer. Combining our new data with already published measurements we redetermine the CoRoT-9 system parameters and find good agreement with the published values. We uncover a higher significance for the small but non-zero eccentricity of CoRoT-9b (e=0.133^+0.042^_-0.037_) and find no evidence for additional planets in the system. We use simulations of planet-planet scattering to show that the eccentricity of CoRoT-9b may have been generated by an instability in which a ~50M_{earth}_ planet was ejected from the system. This scattering would not have produced a spin-orbit misalignment, so we predict that the CoRoT-9b orbit should lie within a few degrees of the initial plane of the protoplanetary disk. As a consequence, any significant stellar obliquity would indicate that the disk was primordially tilted.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A119
- Title:
- CoRoT red giants abundances
- Short Name:
- J/A+A/564/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A precise characterisation of the red giants in the seismology fields of the CoRoT satellite is a prerequisite for further in-depth seismic modelling. High-resolution FEROS and HARPS spectra were obtained as part of the ground-based follow-up campaigns for 19 targets holding great asteroseismic potential. These data are used to accurately estimate in a self-consistent manner their fundamental parameters and the abundances of 16 chemical species. Some powerful probes of mixing are investigated (the Li and CNO abundances, as well as the carbon isotopic ratio in a few cases). The information provided by the spectroscopic and seismic data is combined to provide more accurate physical parameters and abundances. The stars in our sample follow the general trends between various abundance ratios and the metallicity observed in stars of the Galactic disk. After allowance is made for the chemical evolution of the interstellar medium, the observational signature of internal mixing phenomena is revealed through the detection at the stellar surface of the products of the CN and, in the case of the most massive stars, NeNa cycles. Together with the asteroseismic constraints, these data will pave the way for a detailed theoretical investigation of the physical processes responsible for the transport of chemical elements in evolved, low- and intermediate-mass stars.
- ID:
- ivo://idoc.d2s/corot/redgiants-conesearch
- Title:
- CoRoT Red Giants D2S ConeSearch
- Short Name:
- CoRoT_N2_RedGia
- Date:
- 13 May 2019 17:26:29
- Publisher:
- IDOC D2S
- Description:
- This catalog includes CoRoT targets from the exoplanet channel which were identified as possible red giants and actually presents acoustic oscillations of solar-like type, as published by Hekker et al. (A&A, 2009, vol. 506, p. 465).
4377. CoRoT space mission. I.
- ID:
- ivo://CDS.VizieR/J/A+A/482/L17
- Title:
- CoRoT space mission. I.
- Short Name:
- J/A+A/482/L17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The pioneer space mission for photometric planet searches, CoRoT, steadily monitors about 12000 stars in each of its fields of view. Transit candidates can be detected early in the processing of the data and before the end of a run of observation. We report the detection of the first planet discovered by CoRoT and characterizing it with the help of follow-up observations.
- ID:
- ivo://nasa.heasarc/corotexlog
- Title:
- CoRoT Stellar Targets for Exoplanet Detection Observation Log
- Short Name:
- COROTEXLOG
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- CoRoT was a space astronomy mission devoted to the study of the variability with time of stars' brightness, with an extremely high accuracy (100 times better than from the ground), for very long durations (up to 150 days) and with a very high duty cycle (more than 90%). The mission was led by CNES in association with four French laboratories, and 7 participating countries and agencies (Austria, Belgium, Brazil, Germany, Spain, and the ESA Science Programme). The satellite is composed of a PROTEUS platform (the 3rd in the series), and a unique instrument: a stellar photometer. It was launched on December 27th, 2006 on a Soyuz Rocket, from Baikonour. The mission has lasted almost 6 years (the nominal 3 years duration and a 3 years extension) and has observed more than 160,000 stars. It suddenly stopped sending data on November 2nd, 2012. CoRoT performed Ultra High Precision Photometry of Stars to detect and characterize the variability of their luminosity with two main objectives: (i) the variability of the object itself: oscillations, rotation, magnetic activity, etc.; (ii) variability due to external causes such as bodies in orbit around the star: planets and companion stars. The original scientific objectives were focused on the study of stellar pulsations (asteroseismology) to probe the internal structure of stars, and the detection of small exoplanets through their transit in front of their host star, and the measurement of their sizes. This lead to the introduction of two modes of observations, working simultaneously: - The bright star mode dedicated to very precise seismology of a small sample (171) of bright and nearby stars (presented in the file named "Bright_star.dat" in the CDS version at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/">https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/</a>): these data are not included in this HEASARC table, notice; - The faint star mode, observing a very large number of stars at the same time, to detect transits, which are rare events, as they imply the alignment of the star, the planet and the observer (these data are presented in the file named "Faint_star.dat" in the CDS version at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/">https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/</a>): this HEASARC table is based on this sample. The large amount of data gathered in this mode mode turned out to be extremely fruitful for many topics of stellar physics. Due to project constraints, two regions of the sky were accessible (circles of 10 degrees centered on the equator around Right Ascensions of 06<sup>h</sup> 50<sup>m</sup> and 18<sup>h</sup> 50<sup>m</sup>). They are called the CoRoT 'eyes': the first one is called the "anticenter" eye, whereas the second one is called the "center eye". Each pointing covers 1.4 x 2.8 square degrees. The CoRoT project is still processing the data, aiming at removing instrumental artifacts and defects. Therefore the format and content of the catalog is still somewhat evolving. More details on the data can be found in the file <a href="http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/CoRoT_N2_versions_30sept2014.pdf">http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/CoRoT_N2_versions_30sept2014.pdf</a>. More details on the CoRoT N2 data may be found in the documentation file <a href="http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/DescriptionN2v1.5.pdf">http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/DescriptionN2v1.5.pdf</a>. This HEASARC table contains information on stars observed by CoRoT in its exoplanet detection program. A few percent of these stars have 2 entries since they were observed in different windows (as specified by the corot_window_id parameter) in a subsequent observing run to the initial run in which they were observed. Each entry in this table corresponds to the unique specification of target and corot_window_id, each with a link to its associated N2 data products. The original names of the parameters in this table, as given in the CoRoT mission documentation, are given in square brackets at the end of the parameter descriptions listed below. This table was created by the HEASARC in May 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot">CDS Catalog B/corot</a> file Faint_star.dat. The HEASARC routinely updates this table after updates are made to the CDS version of this catalog. This is a service provided by NASA HEASARC .
4379. CoRoT transit catalogue
- ID:
- ivo://CDS.VizieR/J/A+A/619/A97
- Title:
- CoRoT transit catalogue
- Short Name:
- J/A+A/619/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT space mission observed 163665 stars over 26 stellar fields in the faint star channel. The exoplanet teams detected a total of 4123 transit-like features in the 177454 light curves. We present the complete re-analysis of all these detections carried out 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. From the initial list of transit-like features, 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. We provide the catalogue of all these transit-like features, including false alarms. For the planet candidates, the catalogue gives not only their transit parameters but also the products of their light curve modelling: reduced radius, reduced semi-major axis, and impact parameter, together with a summary of the outcome of follow-up observations when carried out and their current status. For the detached eclipsing binaries, the catalogue provides, in addition to their transit parameters, a simple visual classification. Among the planet candidates whose nature remains unresolved, we estimate that eight (within an error of three) planets are still to be identified. After correcting for geometric and sensitivity biases, we derived planet and brown dwarf occurrences and confirm disagreements with Kepler estimates, as previously reported by other authors from the analysis of the first runs: 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/813/96
- Title:
- CO ro-vibrational transitions
- Short Name:
- J/ApJ/813/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present calculated rate coefficients for ro-vibrational transitions of CO in collisions with H atoms for a gas temperature range of 10K<=T<=3000K, based on the recent three-dimensional ab initio H-CO interaction potential of Song et al. (2013JPCA..117.7571S). Rate coefficients for ro-vibrational v=1,j=0-30->v'=0,j' transitions were obtained from scattering cross sections previously computed with the close-coupling (CC) method by Song et al. (2015JChPh.142t4303S). Combining these with the rate coefficients for vibrational v=1-5->v'<v quenching obtained with the infinite-order sudden approximation, we propose a new extrapolation scheme that yields the rate coefficients for ro-vibrational v=2-5,j=0-30->v',j' de-excitation. Cross sections and rate coefficients for ro-vibrational v=2,j=0-30->v'=1,j' transitions calculated with the CC method confirm the effectiveness of this extrapolation scheme. Our calculated and extrapolated rates are very different from those that have been adopted in the modeling of many astrophysical environments. The current work provides the most comprehensive and accurate set of ro-vibrational de-excitation rate coefficients for the astrophysical modeling of the H-CO collision system. The application of the previously available and new data sets in astrophysical slab models shows that the line fluxes typically change by 20%-70% in high temperature environments (800K) with an H/H_2_ ratio of 1; larger changes occur for lower temperatures.
