BINARITY AND PULSATION IN ALGOL-TYPE BINARY SYSTEM SX DRACONIS


SOYDUGAN E. , Kacar Y.

ASTRONOMICAL JOURNAL, vol.145, no.4, 2013 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 145 Issue: 4
  • Publication Date: 2013
  • Doi Number: 10.1088/0004-6256/145/4/87
  • Title of Journal : ASTRONOMICAL JOURNAL
  • Keywords: binaries: eclipsing, stars: individual (SX Draconis), stars: variables: delta Scuti, DELTA-SCUTI STAR, CEPHEID INSTABILITY STRIP, SCT-TYPE PULSATIONS, ECLIPSING BINARIES, PERIOD CHANGES, LIGHT CURVES, PHOTOMETRIC-OBSERVATIONS, STELLAR PARAMETERS, CLOSE BINARIES, DG-LEO

Abstract

Photometric observations of SX Dra were carried out to determine the properties of the components and pulsational characteristics of the more massive pulsational component. Physical parameters of the component stars were obtained by modeling B and V light curves using the Wilson-Devinney code. Results indicate that SX Dra is a semi-detached system with the secondary component filling its Roche lobe. The O-C data showed parabolic and sinusoidal variation. Cyclic variation in the O-C diagram could be the result of the possible magnetic activity of the secondary component instead of the third body. The secular increase in the orbital period of the system can be interpreted as being the result of mass transfer from the secondary component to the primary one at a rate of 2.1 x 10(-7) M-circle dot yr(-1). Results of a time-series analysis performed after removing binary effects indicated that the hot component shows delta Scuti light variations with pulsational periods of 63 and 73 minutes. Spherical harmonic degrees (l) were determined to be 3 for the first frequency and 1-2 for the second frequency.