Modern Comprehensive study of the W UMa System TY Boo
  New CCD three colors light curves of TY Boo were carried out in five nights from February to May 2006 in BVR bandpass using a 50-cm F/8.4 Ritchey Chretien telescope (Ba50) of the Baja Astronomical Observatory (Hungary), and 512*512 Apogee AP-7 CCD camera. A photometric solution of these light curves was obtained by means of Willson-Devinney code. The results showed that the low massive component is hotter than the more massive and cool one, and the temperature difference between the components is Delta T = 249 K. Long term investigation for the period behavior of the system based on all available data shows two stages of increase and similar of decrease, which look like as a periodic behavior. A new light elements yields a new period (p= 0.3171506 day) and shows a period decrease with the rate dP/dE = 5.858*10^(-12) day/cycle or 6.742*10^(-9) day/year or 0.1 second/century. The evolutionary status of the system is discussed. 
M. M. Elkhateeb, M. I. Nouh and A. S. Saad
astro-ph.SR