مقالۀ پژوهشی: حل تحلیلی معادله حاکم بر نوسانات ستارگان تپنده Ap تحت اثر دوران

نوع مقاله : مقاله پژوهشی

نویسنده

استادیار، گروه فیزیک، دانشگاه پیام نور، تهران، ایران

چکیده

ستارگان نوسان کننده سریع    نوع ویژه‌ای از ستارگان  متغییر هستند که در حال تعادل هیدرواستاتیکی نیستند و دوره تپش آن‌ها درمقایسه با سایر ستارگان این گروه بسیار کوتاه و از مرتبه‌ی کمتر از یک ساعت است. این ستارگان دارای نوع طیفی A هستند و در طیف‌شان خطوط مربوط به عناصر نادرخاکی به صورت فزاینده‌ای مشاهده می‌شوند و به همین خاطر به ستارگان  معروف هستند.  در این پژوهش، معادله حرکت ستاره نوسان‌کننده سریع   در حضور یک دوران آرام و یکنواخت به کمک روش اختلالی حل شد و مشخص گردید که تحت اثر دوران سامانه ستاره‌ای، مُدها بین خودشان کوپله می‌شوند. در حقیقت، هر مُد  با   مشخص در اثر دوران ستاره به    مُد جداسازی‌شده که هر یک از این مُدها  مربوط به یک مقدار ویژه‌ای m  نمی‌باشد، بلکه هر مُد تحت اختلال، متشکل از ترکیب خطی   مُد غیراختلالی می‌باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Research Paper: Analytical Solution of the Equation Related to the Oscillations of Ap Pulsating Stars Under the Effect of Rotation

نویسنده [English]

  • Fatemeh Azizi
Department of Physics, Payame Noor University, Tehran, Iran
چکیده [English]

Rapidly oscillating Ap stars are a special type of variable stars that are not in hydrostatic equilibrium. Their pulsation period is very short compared to other stars of this group and is less than one hour. These stars have spectral type A and lines related to rare-earth elements are increasingly observed in their spectrum, so they are known as Ap stars. In this research, the equation of motion of the rapidly oscillating Ap star was solved using the perturbation method in the presence of a smooth and uniform rotation and it was determined that under the effect of rotation in the stellar system, the modes are coupled among themselves. Each mode with a specific l is separated into 2l+1 modes due to rotation, and each of these modes under disturbance does not correspond to a specific value of m, but each mode under perturbation consists of a linear combination of m=2l+1modes.

کلیدواژه‌ها [English]

  • Perturbation Method
  • Stellar Oscillation
  • Pulsating Stars
  • Coupling
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