Photometric study of the eclipsing binary GR Bootis.

We present CCD photometry and low-resolution spectra of the eclipsing binary GR Boo. A new ephemeris is determined based on all the available times of the minimum light. The period analysis reveals that the orbital period is decreasing with a rate of d P / d t = − 2.05 × 10 − 10 d y r − 1 . A photometric analysis for the obtained light curves is performed with the Wilson–Devinney Differential Correction program for the first time. The photometric solutions confirm the W UMa-type nature of the binary system. The mass ratio turns out to be q = 0.985 ± 0.001 . The evolutionary status and physical nature of the binary system are briefly discussed. [ABSTRACT FROM AUTHOR]