LIGHT-CURVE AND PERIOD CHANGES OF AB ANDROMEDAE

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DEMIRCAN O., DERMAN E., AKALIN A., SELAM S. O., MUYESSEROGLU Z.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, cilt.267, sa.1, ss.19-25, 1994 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 267 Sayı: 1
  • Basım Tarihi: 1994
  • Doi Numarası: 10.1093/mnras/267.1.19
  • Dergi Adı: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, INSPEC, Metadex, zbMATH, DIALNET, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.19-25
  • Anahtar Kelimeler: STARS, ACTIVITY, BINARIES, ECLIPSING, STARS, INDIVIDUAL, AB AND STARS, MAGNETIC FIELDS, U-PEGASI, STARS, LUMINOSITY, BINARIES
  • Ankara Üniversitesi Adresli: Evet

Özet

New photoelectric observations of AB And obtained between 1989 and 1992 have been used, together with all available light curves from the literature, to study the light-curve variation of the system and its probable connection with the orbital period variation. A long-term brightness variation in the light levels is detected. The maximum brightness occurred in 1970 (+/- 3 yr). A period study based on all available times of minimum light (of which 22 are newly determined) reveals that the photometric period of the system oscillates around a mean value (P0 almost-equal-to 0.331 890 d) with an oscillation period of almost-equal-to 88.0 +/- 0.2 yr and a half-amplitude of 0.000 003 76 d. Such a variation can be caused by either (i) a period modulation due to the magnetic activity cycle of the active primary component, or (ii) a light-traveltime effect due to a third body in the system. It is shown that the third body, if it exists, can only be a white dwarf; this can be checked by ultraviolet spectroscopy.