A PERIOD STUDY OF SS ARIETIS AND ITS IMPLICATIONS FOR THE MULTIPLICITY OF THE SYSTEM


DEMIRCAN O., SELAM S. O.

ASTRONOMY & ASTROPHYSICS, cilt.267, sa.1, ss.107-110, 1993 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 267 Sayı: 1
  • Basım Tarihi: 1993
  • Dergi Adı: ASTRONOMY & ASTROPHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.107-110
  • Anahtar Kelimeler: STARS, BINARIES, CLOSE, STARS, INDIVIDUAL, SS-ARIETIS, XY-LEONIS, BINARIES
  • Ankara Üniversitesi Adresli: Evet

Özet

A period study of SS Arietis based on all available published times of minima revealed that the photometric period of the system undergoes a continuous cyclic variation with a period of about 44.8 y. The cyclic variation has been discussed in terms of the (i) mass transfer in the system, (ii) magnetically induced deformations in convective envelope, (iii) mass motions in the core of a component star, and (iv) light time effect due to a third body in the system. Due to a smooth curvature of the (O-C) variation we think the most likely explanation of the cyclic period variation is the light time effect. A preliminary solution yields that the hypothetical third body is slightly less massive (M3 almost-equal-to 1.0 M.) than the primary component of SS Ari, and thus it could be visible in the spectrum. Since there is no mention in the literature to any feature attributable to a third body it may be either a binary, just as in the case of the similar binary XY Leo, or a white dwarf. A weak evidence indicating the existence of a small-mass object (M almost-equal-to 0.1 M.) in the system is also present in the observational data. These results emphasize the urgent need of future photometric and spectroscopic observations to settle the discussion on the hypothetical third and probable fourth bodies in the system.