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- ID:
- ivo://CDS.VizieR/J/ApJS/158/193
- Title:
- Catalog of Galactic {beta} Cephei stars
- Short Name:
- J/ApJS/158/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extensive and up-to-date catalog of Galactic {beta} Cephei stars. This catalog is intended to give a comprehensive overview of observational characteristics of all known {beta} Cephei stars, covering information until 2004 June. Ninety-three stars could be confirmed to be {beta} Cephei stars. We use data from more than 250 papers published over the last nearly 100 years, and we provide over 45 notes on individual stars. For some stars we reanalyzed published data or conducted our own analyses. Sixty-one stars were rejected from the final {beta} Cephei list, and 77 stars are suspected to be {beta} Cephei stars. A list of critically selected pulsation frequencies for confirmed {beta} Cephei stars is also presented.
- ID:
- ivo://CDS.VizieR/J/A+A/440/321
- Title:
- Chemical abundances in 43 metal-poor stars
- Short Name:
- J/A+A/440/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni and Ba for 43 metal-poor field stars in the solar neighbourhood, most of them subgiants or turn-off-point stars, with iron abundances [Fe/H] ranging from -0.4 to -3.0. About half of this sample has not been analysed spectroscopically in detail before. Effective temperatures were estimated from uvby photometry, and surface gravities primarily from Hipparcos parallaxes. The analysis is differential relative to the Sun, and carried out with plane-parallel MARCS models. Various sources of error are discussed and found to contribute a total error of about 0.1-0.2dex for most elements, while relative abundances, such as [Ca/Fe], are most probably more accurate. For the oxygen abundances, determined in an NLTE analysis of the 7774{AA} triplet lines, the errors may be somewhat larger.
- ID:
- ivo://CDS.VizieR/J/A+A/326/751
- Title:
- Chemical composition of halo and disk stars
- Short Name:
- J/A+A/326/751
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table A1 lists the Stromgren photometry together with color excesses, E(b-y), photometric metallicities, [Fe/H] , calculated from the calibrations of Schuster & Nissen (1989A&A...221...65S), and absolute magnitudes, M(V), and distances derived with the equations of Nissen & Schuster (1991A&A...251..457N) using the photometric metallicities. Table A2 contains coordinates, proper motions and radial velocities for the program stars as well as distances calculated from the calibrations Nissen & Schuster (1991A&A...251..457N) using the spectroscopic metallicities scaled to our photometric [Fe/H] system. Table A3 gives a list of the 209 spectral lines, which were analyzed, arranged element by element. The table contains the wavelength, the excitation potential of the lower level corresponding to the line, the gf-value, the enhancement factor of the classical van der Waals damping constant, the statistical weight of the upper level, and the equivalent widths measured for the two "standard" stars, HD 22879 and HD 76932. Table A4 contains the measured equivalent widths for all program stars. Table A5 gives abundance ratios and kinematical as well as orbital parameters for the program stars. First are given the data for the 16 disk stars, then follows the 14 halo stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/2106
- Title:
- CU Vir Stroemgren differential photometry
- Short Name:
- J/MNRAS/431/2106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to measure the variations of the magnetic chemically peculiar star CU Vir, we obtained 2821 good Stroemgren uvby photometric values from the Four College Automated Photometric Telescope in the period 1998-2012 and 5529 values from the Solar Mass Ejection Imager in the period 2003-2006, allowing us to further clarify the situation concerning its rotational period, described previously by Pyper et al. (1998A&A...339..822P). Our main result is that the O-C data since 1993 are consistent with a constant period of 0.5207137+/-0.0000010d, which is longer than the period 0.52070308d of Pyper et al. (1998A&A...339..822P). The data during the time period 1993-2012 show no evidence of glitches. The data between 1987 and 1993 correspond to a shorter period of 0.520701d, and the inclusion of those data in the previous study made the published period come out shorter. We also cannot rule out a constantly lengthening period if the data since 1987 are included; however, the fit is slightly better for a constant period. At least five more years of consistent data will be required to distinguish between these two models. Radio astronomy data published since 1998 show phase shifts in the radio emission peaks that are inconsistent with the rotation period inferred from the optical photometry. These shifts may be due to instabilities in the region where the radio emissions originate; they indicate that the photosphere and the upper atmosphere are not rigidly coupled.
- ID:
- ivo://CDS.VizieR/J/other/JAD/18.2
- Title:
- CY Aqr multiband photometry: 2011 season
- Short Name:
- J/other/JAD/18.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on more than a dozen partial nights of filterless CCD photometry combined with Stromgren uvby photomultiplier photometry, we derive 29 new times of maximum light of the SX Phoenicis star CY Aquarii. These times support a linear ephemeris for 2003-2011. In addition, we present uvby light curves for this star. Our dataset displays the smallest residual spread compared to any other substantial dataset published during the last decade.
- ID:
- ivo://CDS.VizieR/J/A+A/441/631
- Title:
- {Delta}a photometry of CP stars
- Short Name:
- J/A+A/441/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have summarized all {Delta}a measurements for galactic field stars (1474 objects) from the literature published over more than two decades. These measurements were, for the first time, compiled and homogeneously analyzed. The {Delta}a intermediate band photometric system samples the depth of the 5200{AA} flux depression by comparing the flux at the center with the adjacent regions with bandwidths of 110{AA} to 230{AA}. Because it was slightly modified over the last three decades, we checked for systematic trends for the different measurements but found no correlations whatsoever. The {Delta}a photometric system is most suitable to detecting magnetic chemically peculiar (CP) stars with high efficiency, but is also capable of detecting a small percentage of non-magnetic CP objects. Furthermore, the groups of (metal-weak) lambda Bootis, as well as classical Be/shell stars, can be successfully investigated. In addition, we also analyzed the behaviour of supergiants (luminosity class I and II). On the basis of apparent normal type objects, the correlation of the 3sigma significance limit and the percentage of positive detection for all groups was derived.
- 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/A+A/438/201
- Title:
- DG Leo uvby differential photometry
- Short Name:
- J/A+A/438/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multi-site and multi-year differential photometry of the triple star DG Leo reveals a complex frequency spectrum that can be modelled as the combination of at least three {delta} Scuti type frequencies in the range 11.5-13c/d (with semi-amplitudes of 2-7mmag) and a superimposed slow variability of larger amplitude. The period of the slow variation fits very well with half the orbital period of the inner spectroscopic binary indicating the presence of ellipsoidal variations caused by the tidally deformed components in a close configuration. These findings, together with the results of a recent spectroscopic analysis (showing that the system consists of a pair of mild Am stars and one A-type component of normal solar composition), infer that DG Leo is an extremely interesting asteroseismic target. Identification of which component(s) of this multiple system is (or are) pulsating and determination of the excited pulsation modes will both contribute to a much better understanding of the non-trivial link between multiplicity, chemical composition, rotation, and pulsation in the lower part of the classical Cepheid instability strip.
- ID:
- ivo://CDS.VizieR/J/A+A/476/881
- Title:
- Differential photometry of FK Com
- Short Name:
- J/A+A/476/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the present work we publish new photometric observations of the very active single giant, FK Com for the time period between the 1st of January 2002 and the 8th of July 2004. The observations have been carried out with three different automatic photometric telescopes: Phoenix 10, Wolfgang and Amadeus, all located in Arizona, USA. Observations contain measurements at the following bands: Johnson U, B and V, Cousins I and Stroemgren b and y. The observations are differential photometry in respect to the primary comparison star HD 117567.
