- ID:
- ivo://CDS.VizieR/J/PASJ/59/335
- Title:
- Properties of 160 F-K disk dwarfs/subgiants
- Short Name:
- J/PASJ/59/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The properties of 160 F, G, and K disk dwarfs/subgiants (including 27 planet-host stars) mostly within -0.6<~[Fe/H]<~+0.4, the Okayama Astrophysical Observatory spectrum collection of which had been made open to the public recently, were extensively investigated with particular attention to determining (1) the mass and the age with the help of theoretical stellar evolution calculations, (2) the kinematic parameters of orbital motions in the Galaxy, and (3) the abundances of 15 elements (Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn) by analyzing the spectra in this database. The resulting characteristics are discussed in terms of several relevant topics of interest, such as a validity check for assuming LTE, the [X/Fe] vs. [Fe/H] diagram containing information on the chemical evolution of the Galactic disk, the age-metallicity-kinematics relation, and the difference/similarity between stars with and without planets.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/534/A133
- Title:
- Proxima Cen chromospheric emission lines
- Short Name:
- J/A+A/534/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extensive identification catalog of chromospheric emission lines in the optical range for a flare on Proxima Centauri. The data were obtained with ESO's Kueyen telescope equipped with the UVES spectrograph on March 9/10, 11/12, 13/14 in 2009. The instrument was operated in dichroic mode (spectral coverage from 3290 to 4500 and from 6400 to 10080{AA}). We tabulate measured wavelength, line flux and FWHM for every line and also provide the rest wavelength from the Moore catalog which was used for identification (Moore, 1972, Nat. Stand. Ref. Data. Ser., 40). Few lines were identified with the NIST database.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A73
- Title:
- PTPS stars. III. The evolved stars sample
- Short Name:
- J/A+A/585/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the complete spectroscopic analysis of 455 stars observed within the Penn State - Torun Centre for Astronomy Planet Search (PTPS) with the High Resolution Spectrograph of the 9.2m Hobby-Eberly Telescope. We also present the total sample of 744 evolved stars of the PTPS and discuss masses of stellar hosts in our and other surveys devoted to evolved planetary systems. Stellar atmospheric parameters were determined through a strictly spectroscopic LTE analysis of equivalent widths of FeI and FeII lines. Rotational velocities were obtained from fitting synthetic spectra. Radial velocities were obtained from fitting a Gaussian function to the cross-correlation function. We determined stellar masses, ages, and luminosities with a Bayesian analysis of theoretical isochrones. The radii were calculated either from derived masses and logg or from Teff and luminosities.
354. PTPS stars IV.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A31
- Title:
- PTPS stars IV.
- Short Name:
- J/A+A/615/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our knowledge of the intrinsic parameters of exoplanets is as precise as our determinations of their stellar hosts parameters. In the case of radial velocity searches for planets, stellar masses appear to be crucial. But before estimating stellar masses properly, detailed spectroscopic analysis is essential. With this paper we conclude a general spectroscopic description of the Pennsylvania-Torun Planet Search (PTPS) sample of stars. We aim at a detailed description of basic parameters of stars representing the complete PTPS sample. We present atmospheric and physical parameters for dwarf stars observed within the PTPS along with updated physical parameters for the remaining stars from this sample after the first Gaia data release. We used high resolution (R=60000) and high signal-to-noise-ratio (S/N=150-250) spectra from the Hobby-Eberly Telescope and its High Resolution Spectrograph. Stellar atmospheric parameters were determined through a strictly spectroscopic local thermodynamic equilibrium analysis (LTE) of the equivalent widths of FeI and FeII lines. Stellar masses, ages, and luminosities were estimated through a Bayesian analysis of theoretical isochrones.
355. RACE-OC project. II.
- ID:
- ivo://CDS.VizieR/J/A+A/532/A10
- Title:
- RACE-OC project. II.
- Short Name:
- J/A+A/532/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotational properties of late-type low-mass members of associations of known age provide a fundamental source of information on stellar internal structure and its evolution. We aim at determining the rotational and magnetic-related activity properties of stars at different stages of evolution. We focus our attention primarily on members of young stellar associations of known ages. Specifically, we extend our previous analysis in Paper I (Messina et al., 2010, Cat. J/A+A/520/A15) to 3 additional young stellar associations beyond 100pc and with ages in the range 6-40Myr: {epsilon} Chamaeleontis (~6Myr), Octans (~20Myr), and Argus (~40Myr). Additional rotational data of {eta} Chamaeleontis and IC 2391 clusters are also considered. Rotational periods were determined by applying the Lomb-Scargle periodogram technique to photometric time-series data obtained by the All Sky Automated Survey (ASAS) and the Wide Angle Search for Planets (SuperWASP) archives. The magnetic activity level was derived from the amplitude of the V light curves.
- ID:
- ivo://CDS.VizieR/J/A+A/513/A29
- Title:
- RACE-OC project: M11 (NGC6705)
- Short Name:
- J/A+A/513/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotation and magnetic activity are intimately linked in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on stellar rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the rotation/activity/age connection. The open cluster M11 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters with different ages. Photometric observations of the open cluster M11 were carried out in June 2004 using LOAO 1m telescope. The rotation periods of the cluster members are determined by Fourier analysis of photometric data time series. We further investigated the relations between the surface activity, characterized by the light curve amplitude, and rotation. We have discovered a total of 75 periodic variables in the M11 FoV, of which 38 are candidate cluster members. Specifically, among cluster members we discovered 6 early-type, 2 eclipsing binaries and 30 bona-fide single periodic late-type variables. Considering the rotation periods of 16 G-type members of the almost coeval 200-Myr M34 cluster, we could determine the rotation period distribution from a more numerous sample of 46 single G stars at an age of about 200-230 Myr and determine a median rotation period P=4.8d. A comparison with the younger M35 cluster (~150Myr) and with the older M37 cluster (~550Myr) shows that G stars rotate slower than younger M35 stars and faster than older M37 stars. The measured variation of the median rotation period is consistent with the scenario of rotational braking of main-sequence spotted stars as they age.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A15
- Title:
- RACE-OC project: YSOs within 100pc
- Short Name:
- J/A+A/520/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Examining the angular momentum of stars and its interplay with their magnetic fields represent a promising way to probe the stellar internal structure and evolution of low-mass stars. We attempt to determine the rotational and magnetic-related activity properties of stars at different stages of evolution.We focused our attention primarily on members of clusters and young stellar associations of known ages. In this study, our targets are 6 young loose stellar associations within 100pc and with ages in the range 8-70Myr: TW Hydrae (~8Myr), beta Pictoris (~10Myr), Tucana/Horologium, Columba, Carina (~30Myr), and AB Doradus (~70Myr). Additional rotational data for alpha Persei and the Pleiades from the literature are also considered.
- ID:
- ivo://CDS.VizieR/J/ApJS/141/503
- Title:
- Radial Velocities for 889 late-type stars
- Short Name:
- J/ApJS/141/503
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report radial velocities for 844 FGKM-type main sequence and subgiant stars and 45 K giants, most of which had either low-precision velocity measurements or none at all. These velocities differ from the standard stars of Udry et al. (1999IAUCo.170..354U) by 0.035km/s (RMS) for the 26 FGK standard stars in common. The zero-point of our velocities differs from that of Udry et al.: <V_present_-V_Udry_>=+0.053km/s. Thus these new velocities agree with the best known standard stars both in precision and zero-point, to well within 0.1km/s. Nonetheless, both these velocities and the standards suffer from three sources of systematic error, namely, convective blueshift, gravitational redshift, and spectral type mismatch of the reference spectrum. These systematic errors are here forced to be zero for G2V stars by using the Sun as reference, with Vesta and day sky as proxies. But for spectral types departing from solar, the systematic errors reach 0.3km/s in the F and K stars and 0.4km/s in M dwarfs. Multiple spectra were obtained for all 889 stars during four years, with the HIRES echelle spectrometer (Vogt et al., 1994, , Proc. Soc. Photo-Opt. Instr. Eng., 2198, 362) on the 10m Keck I telescope and with the "Hamilton" echelle spectrometer fed by either the 3m Shane or the 0.6m Coude Auxilliary (CAT) Telescopes (Vogt, 1987PASP...99.1214V), and 782 of them exhibit velocity scatter less than 0.1km/s. These stars may serve as radial velocity standards if they remain constant in velocity. We found 11 new spectroscopic binaries and report orbital parameters for them.
- ID:
- ivo://CDS.VizieR/J/A+A/512/A45
- Title:
- Radial velocities of BD+20 1790
- Short Name:
- J/A+A/512/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BD+20 1790 is a young active, metal-rich, late-type K5Ve star. We have undertaken a study of stellar activity and kinematics for this star over the past few years. Previous results show a high level of stellar activity, with the presence of prominence-like structures, spots on the surface, and strong flare events, despite the moderate rotational velocity of the star. In addition, radial velocity variations with a semi-amplitude of up to 1km/s were detected. We investigate the nature of these radial velocity variations, in order to determine whether they are due to stellar activity or the reflex motion of the star induced by a companion.
- ID:
- ivo://CDS.VizieR/J/BaltA/11/465
- Title:
- Radial velocities of F5-M stars
- Short Name:
- J/BaltA/11/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocity measurements, made with a CORAVEL type spectrometer, are presented for 211 F5-M stars down to V~13.1 in eight proper motion fields of the MEGA program, located at high Galactic latitudes. These data, together with previous CORAVEL measurements of 116 stars in three of these fields, will be combined with proper motions, photometric distances and metallicities, and ages to investigate the properties of the Galactic disk in the direction perpendicular to the Galactic plane.
