- ID:
- ivo://CDS.VizieR/J/A+A/324/505
- Title:
- Core velocity dispersions of globular clusters
- Short Name:
- J/A+A/324/505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present, for 25 Galactic and 10 old Magellanic globular clusters, projected velocity dispersion ({sigma}_p_) measurements obtained by applying a cross-correlation technique to integrated-light spectra. In order to understand and estimate the statistical errors of these measurements due to small numbers of bright stars dominating the integrated light, we provide an extensive discussion based on detailed numerical simulations. These errors are smaller if the integration area is larger and/or the cluster concentration higher. The simulations show that measurements are reliable when the integrated light within the integration area is brighter than a given magnitude. The statistical errors on the {sigma}_p_ measurements of Magellanic globular clusters are small because of a physically large integration area, whereas they can be important for measurements carried out over small central areas in Galactic clusters. The present observational results are used to outline a few characteristics of the globular cluster fundamental plane. In this respect, the old Magellanic globular clusters appear similar to the Galactic clusters.
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- ID:
- ivo://CDS.VizieR/J/A+A/634/A98
- Title:
- Corona-Australis DANCe. I.
- Short Name:
- J/A+A/634/A98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Corona-Australis is one of the nearest regions to the Sun with recent and ongoing star formation, but the current picture of its stellar (and substellar) content is not complete yet. We take advantage of the second data release of the Gaia space mission to revisit the stellar census and search for additional members of the young stellar association in Corona-Australis. We applied a probabilistic method to infer membership probabilities based on a multidimensional astrometric and photometric data set over a field of 128deg^2^ around the dark clouds of the region. We identify 313 high-probability candidate members to the Corona-Australis association, 262 of which had never been reported as members before. Our sample of members covers the magnitude range between G>~5mag and G<~20mag, and it reveals the existence of two kinematically and spatially distinct subgroups. There is a distributed 'off-cloud' population of stars located in the north of the dark clouds that is twice as numerous as the historically known 'on-cloud' population that is concentrated around the densest cores. By comparing the location of the stars in the HR-diagram with evolutionary models, we show that these two populations are younger than 10Myr. Based on their infrared excess emission, we identify 28 Class II and 215 Class III stars among the sources with available infrared photometry, and we conclude that the frequency of Class~II stars (i.e. `disc-bearing' stars) in the on-cloud region is twice as large as compared to the off-cloud population. The distance derived for the Corona-Australis region based on this updated census is d=149.4^+0.4^_-0.4_pc, which exceeds previous estimates by about 20 pc. In this paper we provide the most complete census of stars in Corona-Australis available to date that can be confirmed with Gaia data. Furthermore, we report on the discovery of an extended and more evolved population of young stars beyond the region of the dark clouds, which was extensively surveyed in the past.
- ID:
- ivo://CDS.VizieR/J/A+A/635/A122
- Title:
- CoRoT-30b and CoRoT-31b radial velocity curves
- Short Name:
- J/A+A/635/A122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery as well as the orbital and physical characterizations of two new transiting giant exoplanets, CoRoT-30 b and CoRoT-31 b, with the CoRoT space telescope. We analyzed two complementary data sets: photometric transit light curves measured by CoRoT, and radial velocity curves measured by the HARPS spectrometer. To derive the absolute masses and radii of the planets, we modeled the stars from available magnitudes and spectra. We find that CoRoT-30 b is a warm Jupiter on a close-to-circular 9.06-day orbit around a G3V star with a semi-major axis of about 0.08AU. It has a radius of 1.01+/-0.08R_Jup_, a mass of 2.90+/-0.22M_Jup_, and therefore a mean density of 3.45+/-0.65g/cm^3^. The hot Jupiter CoRoT-31 b is on a close to circular 4.63-day orbit around a G2 IV star with a semi-major axis of about 0.05AU. It has a radius of 1.46+/-0.30R_Jup_, a mass of 0.84+/-0.34M_Jup_, and therefore a mean density of 0.33+/-0.18g/cm^3^. Neither system seems to support the claim that stars hosting planets are more depleted in lithium. The radii of both planets are close to that of Jupiter, but they differ in mass; CoRoT-30 b is ten times denser than CoRoT-31 b. The core of CoRoT-30 b would weigh between 15 and 75 Earth masses, whereas relatively weak constraints favor no core for CoRoT-31 b. In terms of evolution, the characteristics of CoRoT-31 b appear to be compatible with the high-eccentricity migration scenario, which is not the case for CoRoT-30 b. The angular momentum of CoRoT-31 b is currently too low for the planet to evolve toward synchronization of its orbital revolution with stellar rotation, and the planet will slowly spiral-in while its host star becomes a red giant. CoRoT-30 b is not synchronized either: it looses angular momentum owing to stellar winds and is expected reach steady state in about 2Gyr. CoRoT-30 and 31, as a pair, are a truly remarkable example of diversity in systems with hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A66
- Title:
- CoRoT-8b light and RV curves
- Short Name:
- J/A+A/520/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of CoRoT-8b, a dense small Saturn-class exoplanet that orbits a K1 dwarf in 6.2 days, and we derive its orbital parameters, mass, and radius. We analyzed two complementary data sets: the photometric transit curve of CoRoT-8b as measured by CoRoT and the radial velocity curve of CoRoT-8 as measured by the HARPS spectrometer. We find that CoRoT-8b is on a circular orbit with a semi-major axis of 0.063+/-0.001AU. It has a radius of 0.57+/-0.02RJ, a mass of 0.22+/-0.03MJ, and therefore a mean density 1.6+/-0.1g/cm^3^. With 67% of the size of Saturn and 72% of its mass, CoRoT-8b has a density comparable to that of Neptune (1.76g/cm^3^). We estimate its content in heavy elements to be 47-63 Earth masses, and the mass of its hydrogen-helium envelope to be 7-23 Earth masses. At 0.063AU, the thermal loss of hydrogen of CoRoT-8b should be no more than about 0.1% over an assumed integrated lifetime of 3Ga.
- 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/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://CDS.VizieR/J/MNRAS/484/L8
- Title:
- Correcting HIRES/Keck RVs for systematic errors
- Short Name:
- J/MNRAS/484/L8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The HIRES spectrograph, mounted on the 10-m Keck-I telescope, belongs to a small group of radial-velocity (RV) instruments that produce stellar RVs with long-term precision down to ~1m/s. In 2017, the HIRES team published 64480 RVs of 1699 stars, collected between 1996 and 2014. In this bank of RVs, we identify a sample of RV-quiet stars, whose RV scatter is <10m/s, and use them to reveal two small but significant nightly zero-point effects: a discontinuous jump, caused by major modifications of the instrument in August 2004, and a long-term drift. The size of the 2004 jump is 1.5+/-0.1m/s, and the slow zero-point variations have a typical magnitude of <1m/s. In addition, we find a small but significant correlation between stellar RVs and the time relative to local midnight, indicative of an average intranight drift of 0.051+/-0.004m/s/h. We correct the 64480 HIRES RVs for the systematic effects we find, and make the corrected RVs publicly available. Our findings demonstrate the importance of observing RV-quiet stars, even in the era of simultaneously-calibrated RV spectrographs. We hope that the corrected HIRES RVs will facilitate the search for new planet candidates around the observed stars.
- ID:
- ivo://CDS.VizieR/J/PASJ/56/313
- Title:
- 13CO survey of Mon & CMa molecular clouds
- Short Name:
- J/PASJ/56/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Through a large-scale 13^CO (J=1-0) survey toward a region in Monoceros and Canis Major, we have identified in total 115 clouds.
- ID:
- ivo://CDS.VizieR/J/A+A/417/107
- Title:
- CO velocities in southern HII regions
- Short Name:
- J/A+A/417/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ^12^CO(1-0), ^12^CO(2-1) and/or ^13^CO(1-0) observations in the direction of HII regions located in the southern Galactic plane. The CO lines have been fitted with gaussian lines. For each direction (indicated by the galactic coordinates put in the source identification) we detect several components. The parameter, central position, line width and intensity of every component are listed in tables 2 and 3. In addition, we indicate, in the last two columns the velocity from radio and H{alpha} data of the pointed HII region.