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- ID:
- ivo://CDS.VizieR/III/55
- Title:
- Radial Velocities in Open Clusters
- Short Name:
- III/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This compilation contains more than 5700 individual radial velocities for 370 stars in 4 open clusters.
- ID:
- ivo://CDS.VizieR/III/97A
- Title:
- Radial Velocities in open clusters
- Short Name:
- III/97A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This second part of the bibliography contains 6504 individual radial velocities for 774 stars in 78 open clusters. It is devoted to NGC and IC open clusters. The first part (Mermilliod J.-C., 1979, Bull. Inform. CDS 16,2; catalogue III/55/) contains the data for five nearby open clusters. The collected data have been found in the literature published from 1900 to the end of 1983. This catalog contains also unpublished data which have been delivered to Mermilliod by several authors.
- ID:
- ivo://CDS.VizieR/J/ApJ/639/1069
- Title:
- Radial velocities in the Cas OB6 association
- Short Name:
- J/ApJ/639/1069
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of time-resolved spectroscopy of 13 O-type stars in the Cas OB6 stellar association. We conducted a survey for radial velocity variability in search of binary systems, which are expected to be plentiful in young OB associations.
- ID:
- ivo://CDS.VizieR/J/A+A/488/409
- Title:
- Radial velocities of {alpha} Per stars
- Short Name:
- J/A+A/488/409
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Alpha Persei open cluster (Melotte 20) is one of the nearby clusters (d<500pc) for which a long-term systematic radial-velocity monitoring of the solar-type stars has not been published so far. We undertook an observing program in 1982 to study the membership, duplicity, and rotation of the main-sequence stars and to compare the results with those of the other nearby clusters. Radial-velocity observations of 60 solar-type stars in Mel 20 were obtained with CORAVEL, and of 44 fainter stars with ELODIE spectrographs, in the magnitude range 9.5<V<13.85 The membership of 37 stars from the list compiled by Heckmann is confirmed according to their proper motions, radial velocities, and photometry. We discovered twelve spectroscopic binaries (3 double-lined, 8 single-lined, 1 suspected) among the members and determined an orbit for the double-lined binary He 848. The observed frequency of spectroscopic binaries is therefore 32% (12/37). Four stars are photometric binaries. In addition, the membership of 33 stars with AP numbers is supported by the present radial velocities. Two single-lined and three double-lined binaries were detected in this sample. The cluster mean radial velocity is -1.39+/-0.17km/s based on 18 stars within 2{sigma}. We found a systematic difference of 3.67+/-1.48km/s between observed- and astrometric radial velocities. The Alpha Persei cluster members define a tight main sequence in the colour-magnitude diagrams. The remaining scatter observed in the colour- magnitude diagrams and in radial velocities may be due to the difficulty of separating the core Alpha Persei stars from the extended comoving stream.
- ID:
- ivo://CDS.VizieR/J/A+A/496/441
- Title:
- Radial velocities of Berkeley 32 stars
- Short Name:
- J/A+A/496/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measurements of lithium (Li) abundances in open clusters provide a unique tool for following the evolution of this element with age, metallicity, and stellar mass. In spite of the plethora of Li data already available, the behavior of Li in solar-type stars has so far been poorly understood. Using FLAMES/Giraffe on the VLT, we obtained spectra of 157 candidate members of the old, metal-poor cluster Berkeley 32, to determine membership and to study the Li behavior of confirmed members. Radial velocities were measured, allowing us to derive both the cluster velocity and membership information for the sample stars. The Li abundances were obtained from the equivalent width of the Li I 670.8nm feature, using curves of growth.
- ID:
- ivo://CDS.VizieR/J/A+A/448/1001
- Title:
- Radial velocities of B stars in Sco-Cen
- Short Name:
- J/A+A/448/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive single-epoch radial velocities for a sample of 56 B-type stars members of the subgroups Upper Scorpius, Upper Centaurus Lupus and Lower Centaurus Crux of the nearby Sco-Cen OB association. The radial velocity measurements were obtained by means of high-resolution echelle spectra via analysis of individual lines. The internal accuracy obtained in the measurements is estimated to be typically 2-3km/s, but depends on the projected rotational velocity of the target. Radial velocity measurements taken for 2-3 epochs for the targets HD120307, HD142990 and HD139365 are variable and confirm that the y are spectroscopic binaries, as previously identified in the literature. Spectral lines from two stellar components are resolved in the observed spectra of target stars HD133242, HD133955 and HD143018, identifying them as spectroscopic binaries.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/L33
- Title:
- Radial velocities of 2 hot Jupiters in Praesepe
- Short Name:
- J/ApJ/756/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of two giant planets orbiting stars in Praesepe (also known as the Beehive Cluster). These are the first known hot Jupiters in an open cluster and the only planets known to orbit Sun-like, main-sequence stars in a cluster. The planets are detected from Doppler-shifted radial velocities; line bisector spans and activity indices show no correlation with orbital phase, confirming the variations are caused by planetary companions. Pr0201b orbits a V=10.52 late F dwarf with a period of 4.4264+/-0.0070 days and has a minimum mass of 0.540+/-0.039M_Jup_, and Pr0211b orbits a V=12.06 late G dwarf with a period of 2.1451+/-0.0012 days and has a minimum mass of 1.844+/-0.064M_Jup_. The detection of two planets among 53 single members surveyed establishes a lower limit of 3.8^+5.0^_-2.4_% on the hot Jupiter frequency in this metal-rich open cluster. Given the precisely known age of the cluster, this discovery also demonstrates that, in at least two cases, giant planet migration occurred within 600Myr after formation. As we endeavor to learn more about the frequency and formation history of planets, environments with well-determined properties--such as open clusters like Praesepe--may provide essential clues to this end.
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/3197
- Title:
- Radial velocities of Hyades members
- Short Name:
- J/MNRAS/477/3197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the membership of the Hyades open cluster, derive kinematically modelled parallaxes of its members, and study the colour-absolute magnitude diagram of the cluster. We use Gaia DR1 Tycho-Gaia Astrometric Solution (TGAS) data complemented by Hipparcos-2 data for bright stars not contained in TGAS. We supplement the astrometric data with radial velocities collected from a dozen literature sources. By assuming that all cluster members move with the mean cluster velocity to within the velocity dispersion, we use the observed and the expected motions of the stars to determine individual cluster membership probabilities. We subsequently derive improved parallaxes through maximum-likelihood kinematic modelling of the cluster. This method has an iterative component to deal with 'outliers', caused for instance by double stars or escaping members. Our method extends an existing method and supports the mixed presence of stars with and without radial velocities. We find 251 candidate members, 200 of which have a literature radial velocity, and 70 of which are new candidate members with TGAS astrometry. The cluster is roughly spherical in its centre but significantly flattened at larger radii. The observed colour-absolute magnitude diagram shows a clear binary sequence. The kinematically modelled parallaxes that we derive are a factor ~1.7/2.9 more precise than the TGAS/ Hipparcos-2 values and allow us to derive an extremely sharp main sequence. This sequence shows evidence for fine-detailed structure that is elegantly explained by the full spectrum turbulence model of convection.
- ID:
- ivo://CDS.VizieR/J/AJ/127/3579
- Title:
- Radial velocities of Hyades stars
- Short Name:
- J/AJ/127/3579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a radial velocity survey of a sample of Hyades stars and discuss the effects of stellar activity on radial velocity measurements. The level of radial velocity scatter due to rotational modulation of stellar surface features for the Hyades is in agreement with the 1997 predictions of Saar and Donahue (1997ApJ...485..319S) - the maximum radial velocity rms of up to ~50m/s, with an average rms of ~16m/s. In this sample of 93 stars we find one new binary, two stars with linear trends indicative of binary companions, and no close-in giant planets. We discuss the limits on extrasolar planet detection in the Hyades and the constraints imposed on radial velocity surveys of young stars.
