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- ID:
- ivo://CDS.VizieR/J/MNRAS/475/478
- Title:
- delta Scuti pulsating stars LAMOST views
- Short Name:
- J/MNRAS/475/478
- Date:
- 07 Dec 2021 13:11:57
- Publisher:
- CDS
- Description:
- About 766 {delta} Scuti stars were observed by LAMOST by 2017 June 16. Stellar atmospheric parameters of 525 variables were determined, while spectral types were obtained for all samples. In the paper, those spectroscopic data are catalogued. We detect a group of 131 unusual and cool variable stars (UCVs) that are distinguished from the normal {delta} Scuti stars (NDSTs). On the H-R diagram and the logg-T diagram, the UCVs are far beyond the red edge of pulsational instability trip. Their effective temperatures are lower than 6700K with periods in the range from 0.09 to 0.22d. NDSTs have metallicity close to that of the Sun as expected, while UCVs are slightly metal poor than NDSTs. The two peaks on the distributions of the period and stellar atmospheric parameters are all caused by the existence of UCVs. When those UCVs are excluded, it is discovered that the effective temperature, the gravitational acceleration, and the metallicity all are correlated with the pulsating period for NDSTs and their physical properties and evolutionary states are discussed. Detection of those UCVs indicates that about 25 per cent of the known {delta} Scuti stars may be misclassified. However, if some of them are confirmed to be pulsating stars, they will be a new-type pulsator and their investigations will shed light on theoretical instability domains and on the theories of interacting between the pulsation and the convection of solar-type stars. Meanwhile, 88 {delta} Scuti stars are detected to be the candidates of binary or multiple systems.
- ID:
- ivo://CDS.VizieR/J/A+AS/122/131
- Title:
- Delta Scuti rotational velocities and Teff
- Short Name:
- J/A+AS/122/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Projected rotational velocities and effective temperatures for 68 delta Sct stars as well as 41 non-variable stars of similar spectral type and luminosity are presented here. The observations were performed between 1990 and 1994 at two different observatories: the Observatorio del Roque de los Muchachos (La Palma, Spain) and the McDonald Observatory (Texas, USA).
4314. Delta Scuti stars
- ID:
- ivo://CDS.VizieR/J/A+AS/144/469
- Title:
- Delta Scuti stars
- Short Name:
- J/A+AS/144/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive and up-dated list of {delta} Sct stars is presented here. More than 500 papers, published during the last few years, have been revised and 341 new variables have been added to our last list, six years ago. This catalogue is intended to be a comprehensive review on the observational characteristics of all the {delta} Sct stars known until now, including stars contained in earlier catalogues together with other new discovered variables, covering information published until January 2000. In summary, 636 variables, 1149 references and 182 individual notes are presented in this new list.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/2491
- Title:
- delta Scuti stars seismic and physical observables
- Short Name:
- J/MNRAS/471/2491
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroseismology is witnessing a revolution, thanks to high-precise asteroseismic space data (MOST, COROT, Kepler, BRITE) and their large ground-based follow-up programs. Those instruments have provided an unprecedented large amount of information, which allows us to scrutinize its statistical properties in the quest for hidden relations among pulsational and/or physical observables. This approach might be particularly useful for stars whose pulsation content is difficult to interpret. This is the case of intermediate-mass classical pulsating stars (i.e. {gamma} Dor, {delta} Scuti, hybrids) for which current theories do not properly predict the observed oscillation spectra. Here, we establish a first step in finding such hidden relations from data mining techniques for these stars. We searched for those hidden relations in a sample of {delta} Scuti and hybrid stars observed by COROT and Kepler (74 and 153, respectively). No significant correlations between pairs of observables were found. However, two statistically significant correlations emerged from multivariable correlations in the observed seismic data, which describe the total number of observed frequencies and the largest one, respectively. Moreover, three different sets of stars were found to cluster according to their frequency density distribution. Such sets are in apparent agreement with the asteroseismic properties commonly accepted for A-F pulsating stars.
- ID:
- ivo://CDS.VizieR/J/A+A/614/A46
- Title:
- delta Scuti stars <Teff>-{nu}max relation
- Short Name:
- J/A+A/614/A46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CoRoT and Kepler high-precision photometric data allowed the detection and characterization of the oscillation parameters in stars other than the Sun. Moreover, thanks to the scaling relations, it is possible to estimate masses and radii for thousands of solar-type oscillating stars. Recently, a {Delta}{nu}-{rho} relation has been found for delta Scuti stars. Now, analysing several hundreds of this kind of stars observed with CoRoT and Kepler, we present an empiric relation between their frequency at maximum power of their oscillation spectra and their effective temperature. Such a relation can be explained with the help of the {kappa}-mechanism and the observed dispersion of the residuals is compatible with they being caused by the gravity-darkening effect.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A59
- Title:
- delta Scuti stars with TESS
- Short Name:
- J/A+A/638/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Thanks to high-precision photometric data legacy from space telescopes like CoRoT and Kepler, the scientific community could detect and characterize the power spectra of hundreds of thousands of stars. Using the scaling relations, it is possible to estimate masses and radii for solar-type pulsators. However, these stars are not the only kind of stellar objects that follow these rules: delta Scuti stars seem to be characterized with seismic indexes such as the large separation. Thanks to long-duration high-cadence TESS light curves, we analysed more than two thousand of this kind of classical pulsators. In that way, we propose the frequency at maximum power as a proper seismic index since it is directly related with the intrinsic temperature, mass and radius of the star. This parameter seems not to be affected by rotation, inclination, extinction or resonances, with the exception of the evolution of the stellar parameters. Furthermore, we can constrain rotation and inclination using the departure of temperature produced by the gravity-darkening effect. This is especially feasible for fast rotators as most of delta Scuti stars seem to be.
- ID:
- ivo://CDS.VizieR/J/PASP/106/1120
- Title:
- Delta Scuti variables. II. DY Her
- Short Name:
- J/PASP/106/1120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper in a series on large-amplitude delta Scuti stars intended to determine Baade-Wesselink radii and luminosities with precision. The first paper (Wilson et al., 1993PASP..105..809W) discussed our method of analysis and its application to EH Librae; in this we discuss the observations and analysis of DY Herculis. Optical and infrared photometry and cross-correlated radial-velocity data have been obtained and analyzed. Fourier representations for the UBVRIJHK light curves and for the radial-velocity curves were used to derive a value for the minimum radius for each of 60 combinations of flux and color index. From these we adopt a mean value for the minimum radius of R_min_=2.77+/-0.20R_{sun}_. When combined with effective temperatures from Breger et al. (1978PASP...90..754B), we find a mean bolometric luminosity of <L_B_>=21.70L_{sun}_ and a mean absolute magnitude of <M_B_>=1.41. The radial excursion is 0.149R_{sun}_. We use the same procedure to improve our results for EH Librae, deriving R_min_ for each of 42 combinations of flux and color index, and obtain mean values of R_min_=2.62+/-0.19R_{sun}_, <L_B_>=24.56L_{sun}_ and <M_B_>=1.27.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/525
- Title:
- DeltaV photometry of visual double stars
- Short Name:
- J/A+AS/136/525
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present angular separations, position angles and {Delta}V instrumental magnitude differences of 83 visual double stars with angular separations around two arcseconds. Our observations were made by means of a CCD detector attached to the Kryonerion 1.2m telescope. 12 of them are common proper motion stars and their components should therefore be stars of common origin.
- ID:
- ivo://CDS.VizieR/VII/234
- Title:
- DENIS catalog of galaxies
- Short Name:
- VII/234
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new, extended and improved version of the provisional I-band catalog of DENIS galaxies. Galaxies not cross-identified with already known galaxies have been visually controlled using the DSS1 images and, occasionally, the coordinates were remeasured. The typical accuracy of coordinates is about 2". The typical error on I-band magnitude is about 0.2mag. The final catalog gives the most common names, the J2000 coordinates, the I-band magnitude, the diameter, the axis ratio and the position angle for about 43000 galaxies. It covers roughly 67% of the southern hemisphere. It is homogeneously sampled up to I=14.5 mag. The data are also available via the LEDA database.