scholarly journals Eclipsing Binaries in the Open Cluster Ruprecht 147. III. The Triple System EPIC 219552514 at the Main-sequence Turnoff

2020 ◽  
Vol 896 (2) ◽  
pp. 162 ◽  
Author(s):  
Guillermo Torres ◽  
Andrew Vanderburg ◽  
Jason L. Curtis ◽  
Adam L. Kraus ◽  
Aaron C. Rizzuto ◽  
...  
Keyword(s):  
Triple System ◽  
Main Sequence ◽  
Open Cluster ◽  
Eclipsing Binaries

scholarly journals Eclipsing Binaries in the Open Cluster Ruprecht 147. IV: The Active Triple System EPIC 219511354

2021 ◽  
Vol 921 (2) ◽  
pp. 133
Author(s):  
Guillermo Torres ◽  
Andrew Vanderburg ◽  
Jason L. Curtis ◽  
Adam L. Kraus ◽  
Eric Gaidos
Keyword(s):  
Triple System ◽  
Open Cluster ◽  
Eclipsing Binaries

Variable Star Identification in the BATC Field of M67

2005 ◽  
Vol 277-279 ◽  
pp. 869-875
Author(s):  
Hwihyun Kim ◽  
Yong Ik Byun
Keyword(s):  
Binary Systems ◽  
Main Sequence ◽  
Variable Star ◽  
Open Cluster ◽  
Open Clusters ◽  
Eclipsing Binaries ◽  
Photometric Variability ◽  
Phase Dispersion ◽  
Star Identification

We present the result of photometric variability investigation for stars in the field of M67. The old open cluster M67, one of the most studied open clusters, shows the sign of significant main-sequence binary population in its color-magnitude diagrams. Identification of eclipsing binaries and follow-up studies will enable us to study the nature of binary population in most direct manner. We used approximately 350 images from the BATC (Beijing-Arizona-Taipei-Connecticut) data archive to examine variability within one square degree field centered on M67. A total of 18 stars were classified to be real variables. Our new discoveries include seven eclipsing binary systems of which two are likely to be W UMa systems. All of these variables were found using the phase dispersion minimization (PDM) method developed by Shin and Byun[11].

scholarly journals SPECTROSCOPIC INVESTIGATIONS OF GALACTIC OPEN CLUSTER COLLINDER 394 – NEW RESULTS

2021 ◽  
Vol 34 ◽  
pp. 65-69
Author(s):  
I.A. Usenko ◽  
A.Yu. Kniazev ◽  
A.S. Miroshnichenko ◽  
S. Danford ◽  
V.V. Kovtyukh ◽  
...  
Keyword(s):  
Inverse Problem ◽  
Main Sequence ◽  
Open Cluster ◽  
Eclipsing Binaries ◽  
Spectroscopic Investigations ◽  
Gaia Dr2

Confident main-sequence (MS) members of the Collinder 394 open cluster are perfect objects to check the correctness of their distances, obtained from the GAIA GR2 (2018) catalogue. The differences in the distances to the open cluster Collinder 394, determined by photometry and from the GAIA parallaxes have raised doubts about the correctness of the latter. Therefore we used spectroscopically determined T eff and loggvalues for these stars from Usenko et al. (2019) and tried to solve the inverse problem: determine radii of these stars using the derived distances and calibrations “T eff - radius” for MS stars and compare with similar ones. For this purpose we used the calibrations from Torres et al. (2010), based on the nearest MS eclipsing binaries and compilations for MS stars from Mamajek (2018). As a result, we obtained relationships that connect T eff , logg, radii, masses, and distances for the confident Collinder 394 MS stars. We have confirmed the correctness of the GAIA DR2 (2018) distances for these stars and determined their radii and masses. The latter estimates turned out to be close to those of the evolutionary masses calculated by the PARSEC model

scholarly journals Tidal Circularization Among the Close Binaries in M67

1992 ◽  
Vol 151 ◽  
pp. 471-472
Author(s):  
David W. Latham ◽  
Robert D. Mathieu ◽  
Alejandra A. E. Milone ◽  
Robert J. Davis
Keyword(s):  
Main Sequence ◽  
Open Cluster ◽  
Radial Velocities ◽  
Spectroscopic Binaries ◽  
Close Binaries ◽  
To Come ◽  
Mirror Telescope

In 1971 Roger Griffin and Jim Gunn began monitoring the radial velocities of most of the members brighter than the main-sequence turnoff in the old open cluster M67, primarily using the 200-inch Hale Telescope. In 1982 the torch was passed to Dave Latham and Bob Mathieu, who began monitoring many of the same stars with the 1.5-meter Tillinghast Reflector and the Multiple-Mirror Telescope on Mt. Hopkins. We have successively combined these two sets of data, plus some additional CORAVEL velocities kindly provided by Michel Mayor, to obtain 20 years of time coverage (e.g. Mathieu et al. 1986). Among the stars brighter than magnitude V = 12.7 we have already published orbits for 22 spectroscopic binaries (Mathieu et al. 1990). At Mt. Hopkins an extension of this survey to many of the cluster members down to magnitude V = 15.5 has already yielded thirteen additional orbital solutions, with the promise of many more to come.

scholarly journals A Search for Main-Sequence Binaries in Globular Clusters

1980 ◽  
Vol 85 ◽  
pp. 357-359 ◽  
Author(s):  
Martha H. Liller
Keyword(s):  
Globular Clusters ◽  
Main Sequence ◽  
Eclipsing Binaries ◽  
Cluster Center ◽  
Distance Modulus ◽  
List Type ◽  
Galactic Latitude ◽  
Plate Material ◽  
Evolved Stars ◽  
Visual Distance

It is becoming increasingly clear that no (or only one or two) binaries occur among the evolved stars in globular clusters. Therefore, if binaries exist at all in these systems, they must be found on or near the main sequence. I have chosen 6 clusters to search for faint eclipsing binaries by the following criteria: (1)the apparent visual distance modulus (Harris 1976) (m-M)V ≤ 14.5 mag;(2)the Peterson and King (1975) concentration class c ≤ 1.5, so that the search can be conducted near or at the cluster center where binaries would most likely be found; and(3)the galactic latitude is sufficiently large to avoid problems of extreme contamination by field stars. The clusters thus chosen are NGC3201, 5139 (Omega Cen), 6121 (M4), 6218 (M12), 6254 (M10), and 6809 (M55). The plate material obtained on three nights with the 4-m telescope at CTIO in 1979, consists of seven to nine plates of each cluster on IIIa-F emulsion with an RG610 filter; the search is being conducted with a blink microscope.

scholarly journals The blue straggler S 1082: A triple system in the old open cluster M 67

2001 ◽  
Vol 375 (2) ◽  
pp. 375-386 ◽  
Author(s):  
M. van den Berg ◽  
J. Orosz ◽  
F. Verbunt ◽  
K. Stassun
Keyword(s):  
Triple System ◽  
Open Cluster ◽  
Blue Straggler

scholarly journals Spectroscopic Binaries in the Open Cluster M67

1992 ◽  
Vol 135 ◽  
pp. 155-157 ◽  
Author(s):  
David W. Latham ◽  
Robert D. Mathieu ◽  
Alejandra A.E. Milone ◽  
Robert J. Davis
Keyword(s):  
Circular Orbit ◽  
Main Sequence ◽  
Open Cluster ◽  
Radial Velocities ◽  
Spectroscopic Binaries ◽  
Eccentric Orbit ◽  
Circular Orbits ◽  
Blue Stragglers ◽  
Short Period ◽  
Blue Straggler

AbstractFor almost 400 members of M67 we have accumulated about 5,000 precise radial velocities. Already we have orbital solutions for more than 32 spectroscopic binaries in M67. Many of these orbits were derived by combining the Palomar and CfA observations, thus extending the time coverage to more than 20 years. The distribution of eccentricity versus period shows evidence for tidal circularization on the main sequence. The transition from circular orbits is fairly clean. Excluding the blue stragglers, the first eccentric orbit has a period of 11.0 days, while the last circular orbit has a period of 12.4 days. For longer periods the distribution of eccentricity is the same as for field stars. The blue straggler S1284 has an eccentric orbit despite its short period of 4.2 days.

scholarly journals WIYN Open Cluster Study: Tidal Interactions in Solar-Type Binaries

2004 ◽  
Vol 215 ◽  
pp. 170-176
Author(s):  
S. Meibom ◽  
R. D. Mathieu
Keyword(s):  
Binary Stars ◽  
Main Sequence ◽  
Open Cluster ◽  
Current Data ◽  
Close Binary ◽  
Tidal Interactions ◽  
Close Binary Stars ◽  
Theoretical Predictions ◽  
Solar Type ◽  
Existing Data

We present an ongoing study on tidal interactions in late-type close binary stars. New results on tidal circularization are combined with existing data to test and constrain theoretical predictions of tidal circularization in the pre-main-sequence (PMS) phase and throughout the main-sequence phase of stellar evolution. Current data suggest that tidal circularization during the PMS phase sets the tidal cutoff period for binary populations younger than ~ 1 Gyr. Binary populations older than ~ 1 Gyr show increasing tidal cutoff periods with age, consistent with active main-sequence tidal circularization.

scholarly journals Cepheid distances from the Baade–Wesselink method

2012 ◽  
Vol 8 (S289) ◽  
pp. 138-144 ◽  
Author(s):  
Wolfgang Gieren ◽  
Jesper Storm ◽  
Nicolas Nardetto ◽  
Alexandre Gallenne ◽  
Grzegorz Pietrzyński ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Surface Brightness ◽  
Recent Progress ◽  
Main Sequence ◽  
Near Infrared ◽  
Open Cluster ◽  
Open Clusters ◽  
Distance Scale ◽  
Systematic Uncertainties ◽  
Classical Cepheids

AbstractRecent progress on Baade–Wesselink (BW)-type techniques to determine the distances to classical Cepheids is reviewed. Particular emphasis is placed on the near-infrared surface-brightness (IRSB) version of the BW method. Its most recent calibration is described and shown to be capable of yielding individual Cepheid distances accurate to 6%, including systematic uncertainties. Cepheid distances from the IRSB method are compared to those determined from open cluster zero-age main-sequence fitting for Cepheids located in Galactic open clusters, yielding excellent agreement between the IRSB and cluster Cepheid distance scales. Results for the Cepheid period–luminosity (PL) relation in near-infrared and optical bands based on IRSB distances and the question of the universality of the Cepheid PL relation are discussed. Results from other implementations of the BW method are compared to the IRSB distance scale and possible reasons for discrepancies are identified.

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