- ID:
- ivo://CDS.VizieR/J/ApJ/859/140
- Title:
- Multi-band magnitudes for W UMa EB* candidates
- Short Name:
- J/ApJ/859/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- W Ursa Majoris (W UMa)-type contact binary systems (CBs) are useful statistical distance indicators because of their large numbers. Here, we establish (orbital) period-luminosity relations (PLRs) in 12 optical to mid-infrared bands (GBVRIJHKsW1W2W3W4) based on 183 nearby W UMa-type CBs with accurate Tycho-Gaia parallaxes. The 1{sigma} dispersion of the PLRs decreases from optical to near- and mid-infrared wavelengths. The minimum scatter, 0.16mag, implies that W UMa-type CBs can be used to recover distances to 7% precision. Applying our newly determined PLRs to 19 open clusters containing W UMa-type CBs demonstrates that the PLR and open cluster CB distance scales are mutually consistent to within 1%. Adopting our PLRs as secondary distance indicators, we compiled a catalog of 55603 CB candidates, of which 80% have distance estimates based on a combination of optical, near-infrared, and mid- infrared photometry. Using Fourier decomposition, 27318 high-probability W UMa-type CBs were selected. The resulting 8% distance accuracy implies that our sample encompasses the largest number of objects with accurate distances within a local volume with a radius of 3kpc available to date. The distribution of W UMa-type CBs in the Galaxy suggests that in different environments, the CB luminosity function may be different: larger numbers of brighter (longer-period) W UMa-type CBs are found in younger environments.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/377/1263
- Title:
- Multiperiodic RR Lyrae in ASAS catalog
- Short Name:
- J/MNRAS/377/1263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The All Sky Automated Survey (ASAS) monitors bright stars (8<V<14mag) south of declination +28{deg}. The ASAS Catalogue of Variable Stars (ACVS) presently contains 50099 objects; among them are 2212 objects classified as RR Lyrae pulsating variables. We use ASAS photometric V-band data to search for multiperiodicity in those stars. We find that 73 of 1435 RRab stars and 49 of 756 RRc stars exhibit the Blazhko effect. We observe a deficiency of RRab Blazhko variables with main pulsation periods greater than 0.65d. The Blazhko periods of RRc stars exhibit a strongly bimodal distribution. During our study we discovered the Blazhko effect with multiple periods in object ASAS 0507473351.9 = SU Col. Blazhko periods of 89.3 and 65.8d and a candidate of 29.5d were identified with periodogram peaks near the first three harmonics of the main pulsation. These observations may inspire new models of the Blazhko effect, which has eluded a consistent theory since its discovery about one hundred years ago. Long-term light curve changes were found in 29 stars. We also found 19 Galactic double mode pulsators (RRd), of which four are new discoveries, raising the number of ASAS discoveries of such objects to 16, out of 27 known in the field of our Galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2986
- Title:
- Multiplicity of contact binaries
- Short Name:
- J/AJ/131/2986
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have attempted to establish observational evidence for the presence of distant companions that may have acquired and/or absorbed angular momentum during the evolution of multiple systems, thus facilitating or enabling the formation of contact binaries. In this preliminary investigation we use several techniques (some of them distance- independent) and mostly disregard the detection biases of individual techniques in an attempt to establish a lower limit to the frequency of triple systems. While the whole sample of 151 contact binary stars brighter than V_max_=10mag gives a firm lower limit of 42%{+/-}5%, the corresponding number for the much better observed northern-sky subsample is 59%{+/-}8%. These estimates indicate that most contact binary stars exist in multiple systems.
- ID:
- ivo://CDS.VizieR/J/AJ/156/148
- Title:
- Multiwavelength photometry of RCB stars
- Short Name:
- J/AJ/156/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by the Infrared Astronomical Satellite. RCB stars are carbon-rich supergiants characterized by their extreme hydrogen deficiency and their irregular and spectacular declines in brightness (up to 9 mag). We have analyzed new and archival Spitzer Space Telescope and Herschel Space Observatory data of the envelopes of seven RCB stars to examine the morphology and investigate the origin of these dusty shells. Herschel, in particular, has revealed the first-ever bow shock associated with an RCB star with its observations of SU Tauri. These data have allowed the assembly of the most comprehensive spectral energy distributions (SEDs) of these stars with multiwavelength data from the ultraviolet to the submillimeter. Radiative transfer modeling of the SEDs implies that the RCB stars in this sample are surrounded by an inner warm (up to 1200 K) and an outer cold (up to 200 K) envelope. The outer shells are suggested to contain up to 10^-3^ M_{sun}_ of dust and have existed for up to 10^5^ years depending on the expansion rate of the dust. This age limit indicates that these structures have most likely been formed during the RCB phase.
- ID:
- ivo://CDS.VizieR/J/other/POBol/9.3
- Title:
- 12 M92 variables Photographic observations
- Short Name:
- J/other/POBol/9.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The periods and the light curves of 12 variable stars of the globular cluster M92 have been studied analyzing 176 plates obtained with the 60 cm reflector of Bologna Observatory from 1964 to 1966. Combining the results of the present observations with Hachenberg's (1925, 1933, 1934) and Nassau's (1936), the periods were improved and the O-C diagrams for 9 variables were traced. A parabola well represents the residuals of the variables No. 3, 8 and 11. Variable 9 is likely not strictly periodic.
- ID:
- ivo://CDS.VizieR/II/331
- Title:
- M68 variable star light curves
- Short Name:
- II/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 110 plates of the globular cluster M68, taken during 1951 to 1953 with the 24-inch reflector of the station of Lojano, have been the subject of a photometric investigation.
- ID:
- ivo://CDS.VizieR/J/AJ/107/622
- Title:
- M68 variable star light curves
- Short Name:
- J/AJ/107/622
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 20 CCD images of the globular cluster M68, taken during 14th - 17th April 1989 with the 1.5m Danish telescope in La Silla, have been the subject of a photometric investigation.
558. 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.
