The Instability Strip of M3

buckling of viscoelastic composite plates using the finite strip method

در سال های اخیر، تقاضای استفاده از تئوری خطی ویسکوالاستیسیته بیشتر شده است. با افزایش استفاده از کامپوزیت های پیشرفته در صنایع هوایی و همچنین استفاده روزافزون از مواد پلیمری، اهمیت روش های دقیق طراحی و تحلیل چنین ساختارهایی بیشتر شده است. این مواد جدید از خودشان رفتارهای مکانیکی ارائه می دهند که با تئوری های الاستیسیته و ویسکوزیته، نمی توان آن ها را توصیف کرد. این مواد، خواص ویسکوالاستیک دارند....

The Cepheid Instability Strip in the GAIA Era

We present recent results concerning distance determinations based on the two most popular primary distance indicators, namely classical Cepheids and RR Lyrae. We discuss the problems affecting the Cepheid distance scale, and in particular the dependence of fundamental Period-Luminosity (PL) and Period-Luminosity-Color (PLC) relations on the metal content. The key advantages in using the K-band...

The Instability Strip for Pre–main-sequence Stars

We investigate the pulsational properties of Pre–Main-Sequence (PMS) stars by means of linear and nonlinear calculations. The equilibrium models were taken from models evolved from the protostellar birthline to the ZAMS for masses in the range 1 to 4 M⊙. The nonlinear analysis allows us to define the instability strip of PMS stars in the HR diagram. These models are used to constrain the intern...

The Pulsational Behaviour of Variable Stars in the Lower Part of the Instability Strip

The Lower Part of the Instability Strip: Evolutionary Status of Delta Scuti Stars

The accurate determination of distances from Hip-parcos allows to compare the position in the HR diagram of constant, known variable and chemically peculiar stars in the lower part of the instability strip, including the available new information on variability. Distances are larger and luminosities are slightly higher than those derived from previous calibrations. Masses are then higher. Conse...