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- ID:
- ivo://CDS.VizieR/J/MNRAS/400/1945
- Title:
- Light curves of 261 nearby pulsating M giants
- Short Name:
- J/MNRAS/400/1945
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a 5.5-yr CCD photometric campaign that monitored 261 bright, southern, semiregular variables (SRVs) with relatively precise Hipparcos parallaxes. The data are supplemented with independent photoelectric observations of 34 of the brightest stars, including 11 that were not part of the CCD survey, and a previously unpublished long time- series of VZ Cam. Pulsation periods and amplitudes are established for 247 of these stars, the majority of which have not been determined before. All M giants with sufficient observations for period determination are found to be variable, with 87 per cent of the sample (at a signal-to-noise ratio of >=7.5) exhibiting multiperiodic behaviour. The period ratios of local SRVs are in excellent agreement with those in the Large Magellanic Cloud. Apparent K-band magnitudes are extracted from multiple near-infrared catalogues and analysed to determine the most reliable values. We review the effects of interstellar and circumstellar extinction and calculate absolute K-band magnitudes using revised Hipparcos parallaxes.
- 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.
7957. Light Curves of 29 SNe
- ID:
- ivo://CDS.VizieR/J/AJ/112/2408
- Title:
- Light Curves of 29 SNe
- Short Name:
- J/AJ/112/2408
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BV(RI)_KC_ (see Bessel, 1990PASP..102.1181B) light curves are presented for 27 type Ia supernovae discovered during the course of the Calan/Tololo Survey and for two other SNe Ia observed during the same period. Estimates of the maximum light magnitudes in the B, V, and I bands and the initial decline rate parameter {Delta}m_15_(B) are also given.
- 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/A+A/643/A35
- Title:
- Light curves of 5 supernovae
- Short Name:
- J/A+A/643/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rapid variability before and near the maximum brightness of supernovae has the potential to provide a better understanding of nearly every aspect of supernovae, from the physics of the explosion up to their progenitors and the circumstellar environment. Thanks to modern time-domain optical surveys, which are discovering supernovae in the early stage of their evolution, we have the unique opportunity to capture their intraday behavior before maximum. We present high-cadence photometric monitoring (on the order of seconds-minutes) of the optical light curves of three Type Ia and two Type II SNe over several nights before and near maximum light, using the fast imagers available on the 2.3m Aristarchos telescope at Helmos Observatory and the 1.2m telescope at Kryoneri Observatory in Greece. We applied differential aperture photometry techniques using optimal apertures and we present reconstructed light curves after implementing a seeing correction and the Trend Filtering Algorithm (TFA, Kovacs et al. 2005MNRAS.356..557K). TFA yielded the best results, achieving a typical precision between 0.01 and 0.04mag. We did not detect significant bumps with amplitudes greater than 0.05mag in any of the SNe targets in the VR-, R-, and I- bands light curves obtained. We measured the intraday slope for each light curve, which ranges between -0.37-0.36mag/d in broadband VR, -0.19-0.31mag/d in R band, and -0.13-0.10mag/d in I band. We used SNe light curve fitting templates for SN 2018gv, SN 2018hgc and SN 2018hhn to photometrically classify the light curves and to calculate the time of maximum. We provide values for the maximum of SN 2018zd after applying a low-order polynomial fit and SN 2018hhn for the first time. We conclude that optimal aperture photometry in combination with TFA provides the highest-precision light curves for SNe that are relatively well separated from the centers of their host galaxies. This work aims to inspire the use of ground-based, high-cadence and high-precision photometry to study SNe with the purpose of revealing clues and properties of the explosion environment of both core-collapse and Type Ia supernovae, the explosion mechanisms, binary star interaction and progenitor channels. We suggest monitoring early supernovae light curves in hotter (bluer) bands with a cadence of hours as a promising way of investigating the post-explosion photometric behavior of the progenitor stars.
- 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.