- ID:
- ivo://CDS.VizieR/J/A+A/553/A27
- Title:
- Radial velocities of the HgMn star HD 11733
- Short Name:
- J/A+A/553/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Time series of high-resolution spectra of the late B-type star HD 11753 exhibiting HgMn chemical peculiarity are used to study the surface distribution of different chemical elements and their temporal evolution. High-resolution and high signal-to-noise ratio spectra were obtained using the CORALIE spectrograph at La Silla in 2000, 2009, and 2010. Surface maps of YII, SrII, TiII, and CrII were calculated using the Doppler imaging technique. The results were also compared to equivalent width measurements. The evolution of chemical spots both on short and long time scales were investigated. We determine the binary orbit of HD 11753 and fine-tune the rotation period of the primary. The earlier discovered fast evolution of the chemical spots is confirmed by an analysis using both the chemical spot maps and equivalent width measurements. In addition, a long-term decrease in the overall YII and SrII abundances is discovered. A detailed analysis of the chemical spot configurations reveals some possible evidence that a very weak differential rotation is operating in HD 11753.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/143/107
- Title:
- Radial velocities of TYC 4110-01037-1
- Short Name:
- J/AJ/143/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- TYC 4110-01037-1 has a low-mass stellar companion, whose small mass ratio and short orbital period are atypical among binary systems with solar-like (T_eff_<~6000K) primary stars. Our analysis of TYC 4110-01037-1 reveals it to be a moderately aged (<~5Gyr) solar-like star having a mass of 1.07+/-0.08M_{sun}_ and radius of 0.99+/-0.18R_{sun}_. We analyze 32 radial velocity (RV) measurements from the SDSS-III MARVELS survey as well as 6 supporting RV measurements from the SARG spectrograph on the 3.6m Telescopio Nazionale Galileo telescope obtained over a period of ~2years. The best Keplerian orbital fit parameters were found to have a period of 78.994+/-0.012days, an eccentricity of 0.1095+/-0.0023, and a semi-amplitude of 4199+/-11m/s. We determine the minimum companion mass (if sini=1) to be 97.7+/-5.8M_Jup_. The system's companion to host star mass ratio, >=0.087+/-0.003, places it at the lowest end of observed values for short period stellar companions to solar-like (T_eff_<~6000K) stars. One possible way to create such a system would be if a triple-component stellar multiple broke up into a short period, low q binary during the cluster dispersal phase of its lifetime. A candidate tertiary body has been identified in the system via single-epoch, high contrast imagery. If this object is confirmed to be comoving, we estimate it would be a dM4 star. We present these results in the context of our larger-scale effort to constrain the statistics of low-mass stellar and brown dwarf companions to FGK-type stars via the MARVELS survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/60
- Title:
- Radial velocities of 70 Vir (HD117176)
- Short Name:
- J/ApJ/806/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An on-going effort in the characterization of exoplanetary systems is the accurate determination of host star properties. This effort extends to the relatively bright host stars of planets discovered with the radial velocity method. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) is aiding in these efforts as part of its observational campaign for exoplanet host stars. One of the first known systems is that of 70 Virginis, which harbors a jovian planet in an eccentric orbit. Here we present a complete characterization of this system with a compilation of TERMS photometry, spectroscopy, and interferometry. We provide fundamental properties of the host star through direct interferometric measurements of the radius (1.5% uncertainty) and through spectroscopic analysis. We combined 59 new Keck HIRES radial velocity measurements with the 169 previously published from the ELODIE, Hamilton, and HIRES spectrographs, to calculate a refined orbital solution and construct a transit ephemeris for the planet. These newly determined system characteristics are used to describe the Habitable Zone of the system with a discussion of possible additional planets and related stability simulations. Finally, we present 19 years of precision robotic photometry that constrain stellar activity and rule out central planetary transits for a Jupiter-radius planet at the 5{sigma} level, with reduced significance down to an impact parameter of b=0.95.
- ID:
- ivo://CDS.VizieR/J/AJ/160/251
- Title:
- Radial velocities & orbital data, 5 triple stars
- Short Name:
- J/AJ/160/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Joint analysis of radial velocities and position measurements of five hierarchical stellar systems is undertaken to determine elements of their inner and outer orbits and, whenever possible, their mutual inclinations. The inner and outer periods are 12.9 and 345yr for HD12376 (ADS1613), 1.14 and ~1500yr for HD19971 (ADS2390), 8.3 and 475yr for HD89795 (ADS7338), 1.11 and 40yr for HD152027, 0.69 and 7.4yr for HD190412. The latter system with its coplanar and quasi-circular orbits belongs to the family of compact planetary-like hierarchies, while the orbits in HD12376 have a mutual inclination of 131{deg}.
- ID:
- ivo://CDS.VizieR/J/A+A/653/A78
- Title:
- Radial velocity and activity indicators
- Short Name:
- J/A+A/653/A78
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Due to their low transit probability, the long-period planets are, as a population, only partially probed by transit surveys. Radial velocity surveys thus have a key role to play, in particular for giant planets. Cold Jupiters induce a typical radial velocity semi-amplitude of 10m/s, which is well within the reach of multiple instruments that have now been in operation for more than a decade. We take advantage of the ongoing radial velocity survey with the sophie high-resolution spectrograph, which continues the search started by its predecessor elodie to further characterize the cold Jupiter population. Methods. Analyzing the radial velocity data from six bright solar-like stars taken over a period of up to 15 years, we attempt the detection and confirmation of Keplerian signals. We announce the discovery of six planets, one per system, with minimum masses in the range 4.8-8.3M_jup_ and orbital periods between 200 days and 10 years. The data do not provide enough evidence to support the presence of additional planets in any of these systems. The analysis of stellar activity indicators confirms the planetary nature of the detected signals. These six planets belong to the cold and massive Jupiter population, and four of them populate its eccentric tail. In this respect, HD 80869 b stands out as having one of the most eccentric orbits, with an eccentricity of 0.862^+0.028^_-0.018_. These planets can thus help to better constrain the migration and evolution processes at play in the gas giant population. Furthermore, recent works presenting the correlation between small planets and cold Jupiters indicate that these systems are good candidates to search for small inner planets.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A146
- Title:
- Radial Velocity and BIS measurements of Polaris
- Short Name:
- J/A+A/623/A146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate temporally changing variability amplitudes and the multi- periodicity of the type-I Cepheid Polaris using 162 high-precision radial velocity (RV) and bisector inverse span (BIS) measurements based on optical spectra recorded using Hermes at the 1.2m Flemish Mercator telescope on La Palma, Canary Islands, Spain. Using an empirical template fitting method, we show that Polaris' RV amplitude has been stable to within ~30m/s between September 2011 and November 2018. We apply the template fitting method to publicly accessible, homogeneous RV data sets from the literature and provide an updated solution of Polaris' eccentric 29.3yr orbit. While the inferred pulsation-induced RV amplitudes differ among individual data sets, we find no evidence for time-variable RV amplitudes in any of the separately considered, homogeneous data sets. Additionally, we find that increasing photometric amplitudes determined using SMEI photometry are likely spurious detections due to as yet ill-understood systematic effects of instrumental origin. Given this confusing situation, further analysis of high-quality homogeneous data sets with well-understood systematics is required to confidently establish whether Polaris' variability amplitude is subject to change over time. We confirm periodic bisector variability periods of 3.97d and 40.22d using Hermes BIS measurements and identify a third signal at a period of 60.17d. Although the 60.17d signal dominates the BIS periodogram, we caution that this signal may not be independent of the 40.22d signal. Finally, we show that the 40.22d signal cannot be explained by stellar rotation. Further long-term, high-quality spectroscopic monitoring is required to unravel the complete set of Polaris' periodic signals, which has the potential to provide unprecedented insights into the evolution of Cepheid variables.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A27
- Title:
- Radial velocity and photometry for GJ3470
- Short Name:
- J/A+A/546/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the discovery of GJ 3470b, a transiting hot Uranus of mass m_p_=14.0+/-1.8M_{earth}_, radius R_p_=4.2+/-0.6R_{earth}_ and period P=3.3371+/-0.0002-day. Its host star is a nearby (d=25.2+/-2.9pc) M1.5 dwarf of mass M_star_=0.54+/-0.07M_{sun}_ and radius R_star_=0.50+/-0.06R_{sun}_. The detection was made during a radial-velocity campaign with Harps that focused on the search for short-period planets orbiting M dwarfs. Once the planet was discovered and the transit-search window narrowed to about 10% of an orbital period, a photometric search started with Trappist and quickly detected the ingress of the planet. Additional observations with Trappist, EulerCam and Nites definitely confirmed the transiting nature of GJ3470b and allowed the determination of its true mass and radius. The star's visible or infrared brightness (Vmag=12.3, Kmag=8.0), together with a large eclipse depth D=0.57+/-0.05%, ranks GJ 3470 b among the most suitable planets for follow-up characterizations.
- ID:
- ivo://CDS.VizieR/J/AJ/155/24
- Title:
- Radial velocity and planet detectability in alpha Cen
- Short Name:
- J/AJ/155/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use more than a decade of radial-velocity measurements for {alpha} Cen A, B, and Proxima Centauri from the High Accuracy Radial Velocity Planet Searcher, CTIO High Resolution Spectrograph, and the Ultraviolet and Visual Echelle Spectrograph to identify the Msin(i), and orbital periods of planets that could have been detected if they existed. At each point in a mass-period grid, we sample a simulated, Keplerian signal with the precision and cadence of existing data and assess the probability that the signal could have been produced by noise alone. Existing data places detection thresholds in the classically defined habitable zones at about Msin(i) of 53 M_{Earth}_, for {alpha} Cen A, 8.4 M_{Earth}_, for {alpha} Cen B, and 0.47 M_{Earth}_, for Proxima Centauri. Additionally, we examine the impact of systematic errors, or "red noise" in the data. A comparison of white- and red-noise simulations highlights quasi-periodic variability in the radial velocities that may be caused by systematic errors, photospheric velocity signals, or planetary signals. For example, the red-noise simulations show a peak above white-noise simulations at the period of Proxima Centauri b. We also carry out a spectroscopic analysis of the chemical composition of the {alpha} Centauri stars. The stars have super-solar metallicity with ratios of C/O and Mg/Si that are similar to the Sun, suggesting that any small planets in the {alpha} Cen system may be compositionally similar to our terrestrial planets. Although the small projected separation of {alpha} Cen A and B currently hampers extreme-precision radial-velocity measurements, the angular separation is now increasing. By 2019, {alpha} Cen A and B will be ideal targets for renewed Doppler planet surveys.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/1414
- Title:
- Radial velocity changes for 439 white dwarfs
- Short Name:
- J/MNRAS/467/1414
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From a sample of spectra of 439 white dwarfs (WDs) from the ESO-VLT Supernova-Ia Progenitor Survey (SPY), we measure the maximal changes in radial velocity ({Delta}RVmax) between epochs (generally two epochs, separated by up to 470d), and model the observed {Delta}RVmax statistics via Monte Carlo simulations, to constrain the population characteristics of double WDs (DWDs). The DWD fraction among WDs is f_bin_=0.10+/-0.02 (1{sigma}, random) +0.02 (systematic), in the separation range <~4au within which the data are sensitive to binarity. Assuming the distribution of binary separation, a, is a power law, dN/da{prop.to}a^alpha^, at the end of the last common-envelope phase and the start of solely gravitational-wave-driven binary evolution, the constraint by the data is alpha=-1.3+/-0.2(1{sigma}) +/-0.2 (systematic). If these parameters extend to small separations, the implied Galactic WD merger rate per unit stellar mass is R_merge_=(1-80)x10^-13^yr^-1^M_[sun}_^-1^ (2{sigma}), with a likelihood-weighted mean of R_merge_=(7+/-2)x10^-13^yr^-1^M_{sun}_^-1^ (1{sigma}). The Milky Way's specific Type Ia supernova (SN Ia) rate is likely R_Ia_~=1.1x10^-13^yr^-1^M_{sun}_^-1^ and therefore, in terms of rates, a possibly small fraction of all merging DWDs (e.g. those with massive-enough primary WDs) could suffice to produce most or all SNe Ia.
- ID:
- ivo://CDS.VizieR/J/A+A/519/A10
- Title:
- Radial velocity curve of HD 202206
- Short Name:
- J/A+A/519/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Long-term, precise Doppler measurements with the CORALIE spectrograph have revealed the presence of two massive companions to the solar-type star HD 202206. Although the three-body fit of the system is unstable, it was shown that a 5:1 mean motion resonance exists close to the best fit, where the system is stable. It was also hinted that stable solutions with a wide range of mutual inclinations and low O-C were possible. We present here an extensive dynamical study of the HD 202206 system, aiming at constraining the inclinations of the two known companions, from which we derive possible value ranges for the companion masses.
