Photometric Study Of W Uma Type Binary In The Old Cluster Ngc 6791

2011

We present the combined BVI multicolor photometric solutions of seven EW variables in the old open cluster Berkeley 39. The observations were carried out in the B and V passbands from the 2 m telescope at the IUCAA-Girawali Observatory in India. The analysis is done using the 2003 version of the Wilson-Devinney code and the fitted light curves are presented. The light curves appear to be symmetric in all the passbands. The photometric solutions suggest that the variables are W-type systems. The new ephemeris indicates that the orbital periods of the studied variables have not changed during the timespan of observations. Revised orbital period, absolute mass, radius and luminosity of the respective variables are presented. The absolute physical parameters of the variables follow the trend of field EW stars. Comparing the results obtained with the other theoretical works, we suggest that there is an excess loss of mass and angular momentum in these systems which may be due to their short period and relatively young age, possibly due to the presence of a third component or the initial detached period being less than 2 d.

Section: Discussionmentioning

confidence: 99%

CCD photometry of W UMa-type contact binaries in the old open cluster Berkeley 39

Kiron

2011

“…Since no systematic photometric analysis has been carried out to derive the system parameters, especially the mass-ratio for these W UMa type variables discovered in LMC, we have analyzed the light curves of six eclipsing binary systems: S1 (OGLE 053247.54-694403.1), S2 (OGLE 053251.73-700256.2), S3 (OGLE 051206.93-685645.1), S4 (OGLE 050542.01-691725.9), S5 (OGLE 053540.37-695413.9) and S6 . A similar kind of study was carried out on the W UMa type binaries in open clusters: NGC 7789 (Sriram & Vivekananda Rao 2010), Be 39 (Sriram et al 2009), NGC 6791 (Rukmini et al 2005), and Be 33 (Rukmini & Vivekananda Rao 2002). We have used the Wilson-Devinney (W-D) program to derive the various photometric elements and put a constraint on the mass-ratio parameter.…”

Section: Introductionmentioning

confidence: 96%

Photometric study of eclipsing binaries in the Large Magellanic Cloud — I. W UMa type binaries in the Large Magellanic Cloud

Devarapalli

2011

“…From the analysis performed on these systems, it was found that the mass-ratios were close to unity and in one case greater than unity (Rukmini & Vivekananda Rao 2002, Rukmini et al 2005. A detail spectroscopic observation was suggested to know the true nature of these objects.…”

Section: Introductionmentioning

confidence: 97%

“…The old open cluster Berkeley 39 is located in the direction of the galactic anti-centre (α 2000 =7 h 46 m 48 s , and Be 33 (Rukmini & Vivekananda Rao 2002, Rukmini et al 2005. From the analysis performed on these systems, it was found that the mass-ratios were close to unity and in one case greater than unity (Rukmini & Vivekananda Rao 2002, Rukmini et al 2005.…”

Section: Introductionmentioning

confidence: 99%

“…Since no photometric analysis is carried out for the eclipsing binaries present in Be 39 cluster, we have analyzed the light curves of four eclipsing binary systems V1,V4,V7 and V8 which have relatively high and Be 33 (Rukmini & Vivekananda Rao 2002, Rukmini et al 2005. From the analysis performed on these systems, it was found that the mass-ratios were close to unity and in one case greater than unity (Rukmini & Vivekananda Rao 2002, Rukmini et al 2005. A detail spectroscopic observation was suggested to know the true nature of these objects.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photometric study of W UMa type binaries in the old open cluster Berkeley 39

Kiron

2009

The study of W UMa binary systems give a wealth of information about its nature as well as about its parent body (if any), like clusters. In this paper, we present the I passband photometric solutions of four W UMa binaries in the open cluster Berkeley 39 using the latest version of W-D program. The result shows that, two binary systems are W-subtype W UMa binary systems and another two systems are H-subtype W UMa binary systems. No third body is found in any of the four systems. We found a correlation between the period and mass-ratio as well as temperature and mass-ratio for the respective variables which is similar to the relationship between mass ratio and total mass of the contact binaries as shown by van't Veer (1996) and Li et al. (2008).