تفاصيل الوثيقة
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نوع الوثيقة |
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مقال في مجلة دورية |
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عنوان الوثيقة |
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Computational developments for distance determination of stellar groups Computational developments for distance determination of stellar groups |
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الموضوع |
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علم الفلك |
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لغة الوثيقة |
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الانجليزية |
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المستخلص |
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In this paper, we consider a statistical method for distance determination of stellar groups. The method depends on the assumption that the members of the group scatter around a mean absolute magnitude in Gaussian distribution. The mean apparent magnitude of the members is then expressed by frequency function, so as to correct for observational incompleteness at the faint end. The problem reduces to the solution of a highly transcendental equation for a given magnitude parameter α. For the computational developments of the problem, continued fraction by the Top-Down algorithm was developed and applied for the evaluation of the error function erf(z). The distance equation Λ(y) = 0 was solved by an iterative method of second order of convergence using homotopy continuation technique. This technique does not need any prior knowledge of the initial guess, a property which avoids the critical situations between divergent and very slow convergent solutions, that may exist in the applications of other iterative methods depending on initial guess. Finally, we apply the method for the nearby main sequence late type stars assuming that the stars of each group of the same spectral type scatter around a mean absolute magnitude in a Gaussian distribution. The accuracies of the numerical results are satisfactory, in that, the percentage errors between r and the mean values are respectively: (2.4%, 1.6%, 0.72%, 0.66%, 3.5%, 2.4%, 2%, 2.5%, 0.9%) for the stars of spectral types: (F5V, F6V, F7V, F8V, F9V, G0V, G2V, G5V, G8V). |
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ردمد |
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0250-6335 |
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اسم الدورية |
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Journal of Astrophysics and Astronomy |
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المجلد |
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31 |
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العدد |
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1 |
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سنة النشر |
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1431 هـ
2010 م |
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نوع المقالة |
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مقالة علمية |
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تاريخ الاضافة على الموقع |
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Monday, November 21, 2011 |
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الباحثون
| محمد عادل شرف | Sharaf, Mohamed A | باحث | دكتوراه | sharaf_adel@hotmail.com |
| A M Sendi | Sendi, A M | باحث | | |
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الرجوع إلى صفحة الأبحاث
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