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812. M37 variable stars
- ID:
- ivo://CDS.VizieR/J/ApJ/675/1254
- Title:
- M37 variable stars
- Short Name:
- J/ApJ/675/1254
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a deep (15~<r~<23 ), 20 night survey for transiting planets in the intermediate-age (~550Myr) open cluster M37 (NGC 2099) using the Megacam wide-field mosaic CCD camera on the 6.5m MMT. In this paper we present a catalog and light curves for 1445 variable stars; 1430 (99%) of these are new discoveries. We have discovered 20 new eclipsing binaries and 31 new short-period (P<1day) pulsating stars. The bulk of the variables are most likely rapidly rotating young low-mass stars, including a substantial number (>~500) that are members of the cluster. We identify and analyze five particularly interesting individual variables, including a previously identified variable that we suggest is probably a hybrid gamma Doradus/delta Scuti pulsator, two possible quiescent cataclysmic variables, a detached eclipsing binary (DEB) with at least one gamma Doradus pulsating component (only the second such variable found in an eclipsing binary), and a low-mass (M_P_~M_S~0.6M_{sun}_ DEB that is a possible cluster member. A preliminary determination of the physical parameters for the DEB+gamma Doradus system yields M_P_=1.58+/-0.04M_{sun}_, M_S_=1.58+/-0.04M_{sun}_, R_P_=1.39+/-0.07R_{sun}_, and R_S_=1.38+/-0.07R_{sun}_.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/1060
- Title:
- M67 variable stars from Kepler/K2-Campaign-5
- Short Name:
- J/MNRAS/459/1060
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the photometric variability of stars in the M 67 field using Kepler/K2-Campaign-5 light curves. Variabilities and periods were determined for 639 stars. The mean photometric period of 28 single Sun-like members stars in M 67 is 23.4+/-1.2d. This corresponds to a gyro-age of 3.7+/-0.3Gyr, assuming the periods can be associated with rotation. The intrinsic variabilities of the solar analogues are greater than the Sun's variability, as measure from VIRGO fluxes. We also find evidence that the single cluster members have a different distribution of variability than the binary members.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/2337
- Title:
- M67 variable stars photometry
- Short Name:
- J/MNRAS/455/2337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we continue the release of high-level data products from the multiyear photometric survey collected at the 67/92cm Schmidt Telescope in Asiago. The primary goal of the survey is to discover and to characterize variable objects and exoplanetary transits in four fields containing five nearby open clusters spanning a broad range of ages. This second paper releases a photometric catalogue, in five photometric bands, of the solar-age, solar-metallicity open cluster M 67 (NGC 2682). Proper motions are derived comparing the positions observed in 2013 at the Asiago's Schmidt Telescope with those extracted from Wide Field Imager@2.2m Max-Planck-Gesellschaft/European Southern Obseratory images in 2000. We also analyse the variable sources within M 67. We detected 68 variables, 43 of which are new detection. Variable periods and proper-motion memberships of a large majority of sources in our catalogue are improved with respect to previous releases. The entire catalogue will be available in electronic format. Besides the general interest on an improved catalogue, this work will be particularly useful because of: (1) the imminent release of Kepler/K2 Campaign-5 data of this clusters, for which our catalogue will provide an excellent, high spatial resolution input list, and (2) characterization of the M 67 stars which are targets of intense High Accuracy Radial velocity Planet Searcher and High Accuracy Radial velocity Planet Searcher for the Northern hemisphere radial-velocity surveys for planet search.
- ID:
- ivo://CDS.VizieR/J/A+A/358/547
- Title:
- M53 variable stars V light curves
- Short Name:
- J/A+A/358/547
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the application of the Image Subtraction Method (ISM) to the CCD observations of the central region of globular cluster M53. We have obtained good quality light curves of the 23 previously known RR Lyrae stars in this cluster. We have also confirmed the variability of ten RR Lyrae candidates discovered by Kravtsov. Moreover, we have found four new variables of this type in the core of the cluster. Altogether, the light curves have been obtained for 37 RR Lyrae stars. We also report the discovery of variations in six cluster bright giants.
- ID:
- ivo://CDS.VizieR/J/other/MmSAI/20.63
- Title:
- M30 V1-V3 variable light curves
- Short Name:
- J/other/MmSAI/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 175 plates of the globular cluster M30 in Capricornus, taken mainly in the years 1946, 1947 and 1948, with the 24-inch reflector, have been the object of a photometric investigation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/164
- Title:
- MW Lyr BV(RI)c light curves
- Short Name:
- J/MNRAS/391/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained the most extensive and most accurate photometric data of a Blazhko variable MW Lyrae (MW Lyr) during the 2006-2007 observing seasons. The data within each 0.05 phase bin of the modulation period (P_m_=1/f_m_) cover the entire light cycle of the primary pulsation period (P_0_=1/f_0_) , making possible a very rigorous and complete analysis.
- ID:
- ivo://CDS.VizieR/J/AJ/126/175
- Title:
- M31Y eclipsing binaries and Cepheids
- Short Name:
- J/AJ/126/175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The DIRECT Project aims to obtain direct distances to two Local Group galaxies, M31 and M33, which occupy a crucial position near the base of the cosmological distance ladder. The first step is to search for detached eclipsing binaries (DEBs) and Cepheids using 1m class telescopes to select good candidates, which will be followed up spectroscopically on 6.510m class telescopes. In this ninth paper, we present a catalog of variable stars discovered with image subtraction in field M31Y (RA=10.97{deg}, DE=41.69{deg}; J2000.0). The data were obtained with the Fred Lawrence Whipple Observatory 1.2m telescope on 25 nights, over a period of 6 months. In our search covering 22x22, we discovered 41 eclipsing binaries, 126 Cepheids, and 97 other periodic or nonperiodic variables, including a luminous blue variable candidate, a nova, and a Galactic cataclysmic variable. The catalog of variables, as well as their photometry and finding charts, is available electronically via anonymous ftp and the World Wide Web, at http://cfa-www.harvard.edu/~kstanek/DIRECT . The complete set of the CCD frames is available upon request.
- ID:
- ivo://CDS.VizieR/J/A+A/455/303
- Title:
- Nainital-Cape Survey. II. Null results
- Short Name:
- J/A+A/455/303
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We search for photometric variability in chemically peculiar A type stars in the northern hemisphere. High-speed photometric observations of Ap and Am star candidates have been carried out from ARIES (Manora Peak, Nainital) using a three-channel fast photometer attached to the ARIES 104-cm Sampurnanand telescope.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A116
- Title:
- Nainital-Cape Survey. IV.
- Short Name:
- J/A+A/590/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Nainital-Cape Survey is a dedicated ongoing Survey programme to search for and study pulsational variability in chemically peculiar (CP) stars to understand their internal structure and evolution. The main aims of this Survey are to find new pulsating Ap and Am stars in the northern and southern hemisphere and to perform asteroseismic studies of these new pulsators. The Survey is conducted using high-speed photometry. The candidate stars were selected on the basis of having Stromgren photometric indices similar to those of known pulsating CP stars. Over the last decade a total of 337 candidate pulsating CP stars were observed for the Nainital-Cape Survey, making it one of the longest ground-based surveys for pulsation in CP stars in terms of time span and sample size. The previous papers of this series presented seven new pulsating variables and 229 null results. In this paper we present the light curves, frequency spectra and various astrophysical parameters of the 108 additional CP stars observed since the last reported results. We also tabulated the basic physical parameters of the known roAp stars. As a part of establishing the detection limits in the Nainital-Cape Survey, we investigated the scintillation noise level at the two observing sites used in this Survey, Sutherland and Nainital, by comparing the combined frequency spectra stars observed from each location. Our analysis shows that both the sites permit the detection of variations of the order of 0.6-milli-magnitude (mmag) in the frequency range 1-4mHz, Sutherland is on average marginally better.
