A comprehensive photometric and spectroscopic analysis of the variable TYC 5532-1333-1 (TYC) along with an investigation of its orbital period variation is presented for the first time. The B- and V-band photometric study indicates that TYC is an intermediate contact binary with degree of contact and mass ratio of 34 per cent and ∼0.24, respectively. The derived equivalent widths from the spectroscopic study of Hα and   Na-I lines reveal phase-dependent variation and mutual correlation. Using the available times of minimum light, an investigation of orbital period variation shows a long-term decrease at a rate of 3.98 × 10 −6 d yr−1. Expected causes for such decline in the orbital period could be angular momentum loss and a quasi-sinusoidal variation due to light-time effect probably caused by a third-body companion. The minimum mass of the third body (M3) was derived to be $0.65 \, \mathrm{M}_{\odot }$. Our presented study is an attempt to evaluate and understand the evolutionary state of above-mentioned neglected contact binary.

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We present CCD photometric observations of an eclipsing binary in the direction of the open cluster Praesepe using the 2 m telescope at IUCAA Girawali Observatory, India. Though the system was classified as an eclipsing binary by Pepper et al., detailed investigations have been lacking. The photometric solutions using the Wilson-Devinney code suggest that it is a W-type W UMa system and, interestingly, the system parameters are similar to another contact binary system SW Lac.

The ultrasonic velocity, density and viscosity have been measured for the mixtures of 1-alkanols such as 1-propanol and 1-butanol withN-Ndimethylformamide (DMF) at 303 K. The experimental data have been used to calculate the acoustical parameters namely adiabatic compressibility (β), free length (Lf), free volume (Vf) and internal pressure (πi). The excess values of the above parameters are also evaluated and discussed in the light of molecular interaction existing in the mixtures. It is obvious that there is a formation of hydrogen bonding between DMF and 1-alkanols. Further, the addition of DMF causes dissociation of hydrogen bonded structure of 1-alkanols. The evaluated excess values confirm that the molecular association is more pronounced in system-II comparing to the system-I.

Eclipsing binaries are among the most important sources of information on stellar parameters like radii, masses, luminosities, etc. We present the analysis of six W UMa systems discovered in the Large Magellanic Cloud using the Wilson-Devinney method.