... The spectrum of the brightest star, our Sun, shows several dark gaps perpendicular to the flow of it’s colours (figure 1). These so called spectral absorption lines where discovered in 1802 by the English scientist William Wollaston. ... Some stars as Pollux show a spectrum similar to that of our sun with strong Ca II and Fe II lines, others as Sirius or Vega show strong absorption lines of hydrogen, others, as Mira show very complicated spectra due to molecular absorption lines (see figure 5). ...

... 13, Moscow, 119992 Russia 2 Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz, Karachai-Cherkessian Republic, 369167 Russia Received May 18, 2009 Abstract--Using the method of two-dimensional spectroscopy, we have investigated the kinematics and distribution of the gas and stars at the center of the early-type spiral galaxy NGC 7177 with a mediumscale bar as well as the change in the mean age of the stellar population along the radius. ...

СТУДЕНЧЕСКИЕ ОЛИМПИАДЫ ПО ГЕОМЕТРИИ И ТОПОЛОГИИ http://dfgm.math.msu.su/ les/skopenkov/geomolymp.pdf Обновленная версия статьи Мат. ... расстояние от точки Ai до прямой l. Будем рассматривать прямые l на плоскости, проходящие через точку O. Пусть I+ и I- | ... Найдите наибольшее целое n, для которого на плоскости существует кривая второго порядка, имеющая в точке (0; 1) касание n-го порядка с графиком функции y = cos x. Напомним [Ra03, §§ 22, 23], что если P | ... Возьмем точку a R2 - N . ...