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- ID:
- ivo://CDS.VizieR/J/A+A/632/A95
- Title:
- Light curves of NGC 6910 pulsating stars
- Short Name:
- J/A+A/632/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this study is to obtain the age of the open cluster NGC 6910 by means of ensemble asteroseismology of the early-type pulsating members, to derive their stellar parameters, and to classify the excited modes. We used time-series analysis, performed photometric and spectroscopic mode identification, and calculated grids of evolutionary and seismic models to apply the procedure of ensemble asteroseismology for nine pulsating members of NGC 6910. With two iterations of the procedure of ensemble asteroseismology we derived an age of 10.6^+0.9^_-0.8_Myr for NGC 6910. We also identified the degree l for 8 of 37 modes detected in these stars and classified all modes in terms of p, g, and mixed-mode pulsations. Of the nine pulsating stars examined in the paper, eight are {beta} Cep stars, including three that are hybrid {beta} Cep and slowly pulsating B-type (SPB) pulsators, and one is an SPB star. Interestingly, the least massive {beta} Cep star, NGC 6910-38, has a mass of about 5.6 solar masses. The present theory does not predict unstable p modes in B-type stars with such a low mass. The g modes with relatively high frequencies (>3.5d^-1^), observed in three members of the cluster, are also stable according to seismic modelling. Both findings pose a challenge for theoretical calculations and prompt a revision of the opacities. The procedure of ensemble asteroseismology was found to be successful for NGC 6910 and {chi} Per on the basis of pulsating B-type stars and can therefore be applied to other young open clusters that are rich in such stars.
- ID:
- ivo://CDS.VizieR/J/A+A/404/621
- Title:
- Light curves of ROTSE-I delta Scuti type stars
- Short Name:
- J/A+A/404/621
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-passband CCD photometry of 20 ROTSE-I {delta} Scuti type pulsating stars and 1 RR Lyrae star to re-classify their variable types using the comparison of amplitudes between V and I passbands. For the re-classification, we used a criterion that pulsating stars have larger amplitude differences between passbands than eclipsing binaries because brightness changes of pulsating stars are mainly due to the temperature variations. As a result, only six stars were re-confirmed as {delta} Scuti variables and thirteen stars turned out to be W UMa type eclipsing binaries. The other two stars were identified as one cataclysmic variable and one non-variable, respectively. Our results suggest that a number of ROTSE-I {delta} Scuti type stars, which do not show typical pulsating light curves of high amplitude {delta} Scuti stars, are W UMa type eclipsing binaries.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/25
- Title:
- Light curves of RR Lyrae stars in M3 (NGC5272)
- Short Name:
- J/ApJS/219/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The overtone and multi-mode RR Lyrae stars in the globular cluster M3 are studied using a 200 day long, B,V, and l_c_ time-series photometry obtained in 2012. 70% of the 52 overtone variables observed show some kind of multi-periodicity (with additional frequency at f_0.61_=f_1O_/0.61 frequency ratio, Blazhko effect, double/multi-mode pulsation, and period doubling). A signal at the 0.587 frequency ratio to the fundamental-mode frequency is detected in the double-mode star, V13, which may be identified as the second radial overtone mode. If this mode identification is correct, then V13 is the first RR Lyrae star showing triple-mode pulsation of the first three radial modes. Either the Blazhko effect or the f_0,61_ frequency (or both of these phenomena) appears in seven double-mode stars. The P_1O_/P_F_ period ratio of RRd stars showing the Blazhko effect are anomalous. A displacement of the main frequency component at the fundamental mode with the value of modulation frequency (or its half), is detected in three Blazhko RRd stars that are parallel with the appearance of the overtone-mode pulsation. The f_0.61_ frequency appears in RRc stars that lie at the blue side of the double-mode region and in RRd stars, raising the suspicion that its occurrence may be connected to double-mode pulsation. The changes of the Blazhko and double-mode properties of the stars are also reviewed using the recent and archive photometric data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4590
- Title:
- Light curves of RR Lyrae variables in M31
- Short Name:
- J/MNRAS/478/4590
- Date:
- 10 Dec 2021 13:45:59
- Publisher:
- CDS
- Description:
- We present an analysis of M31 RR Lyrae stars in six different fields using archival imaging from the Hubble Space Telescope. Published data for M31, M33, and several M31 dwarf spheroidal galaxies are also used to study the global properties of RR Lyrae in these systems. From the properties of RR Lyrae stars, we found that the majority of M31 and M33 RRLs are of Oosterhoff I (OoI),while those in M31 dSphs are of Oosterhoff intermediate. The main parameter affecting these Oosterhoff types is likely to be metallicity. Metallicity also plays a role in the lack of RRLs in the high amplitude short period(HASP, defined as those with P<=0.48 and A_V_>=0.75mag) variables in M31 dSphs. This difference in the properties of RRLs between their parent galaxy and satellites, as well as the lack of RRLs in the HASP region in dSphs can also be observed in the Milky Way (MW). Therefore, systems like these dSphs are unlikely to be the main building blocks of the M31 and MW halo.
- ID:
- ivo://CDS.VizieR/J/PAZh/35/451
- Title:
- Light Curves of RS Pup
- Short Name:
- J/PAZh/35/451
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on photographic plates from the Harvard College Observatory, we have made 1492 magnitude estimates for the long-period classical Cepheid RS Pup (P=41.4d). Together with the observations taken from the literature, our data have allowed us to construct an O-C diagram spanning a time interval of 135-years.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A38
- Title:
- Light curves of spotted solar-type stars
- Short Name:
- J/A+A/588/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We perform detailed time series analysis for B- and V-band photometry of 21 young and active solar-type stars to study their spot structures, activity cycles, and differential rotation.
- ID:
- ivo://CDS.VizieR/J/ApJ/780/92
- Title:
- Light curves of the RR Lyr SDSS J015450.17+001500.7
- Short Name:
- J/ApJ/780/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and discuss an extensive data set for the non-Blazhko ab-type RR Lyrae star SDSS J015450+001501, including optical Sloan Digital Sky Survey ugriz light curves and spectroscopic data, LINEAR and Catalina Sky Survey unfiltered optical light curves, and infrared Two Micron All Sky Survey (2MASS) JHKs and Wide-field Infrared Survey Explorer W1 and W2 light curves. Most notable is that light curves obtained by 2MASS include close to 9000 photometric measures collected over 3.3yr and provide an exceedingly precise view of near-infrared variability. These data demonstrate that static atmosphere models are insufficient to explain multiband photometric light-curve behavior and present strong constraints for nonlinear pulsation models for RR Lyrae stars. It is a challenge to modelers to produce theoretical light curves that can explain data presented here, which we make publicly available.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A111
- Title:
- Light curves of two NGC6981 variables
- Short Name:
- J/A+A/553/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the electron multiplying CCD (EMCCD) camera at the Danish 1.54m Telescope at La Silla, Chile. The two variables were not previously detected by conventional CCD imaging because of their proximity to a bright star. This discovery demonstrates that EMCCDs are a powerful tool for performing high-precision time-series photometry in crowded fields and near bright stars, especially when combined with difference image analysis.
- ID:
- ivo://CDS.VizieR/J/other/MmSAI/31.187
- Title:
- Light curves of 12 variables in NGC 6229
- Short Name:
- J/other/MmSAI/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Periods and light curves of 12 variable stars of the globular cluster NGC 6229 have been determined. The photographic magnitudes are given for 4 other variables. Observations were obtained at the Asiago observatory, in the years 1956-57-58.
