Photometric study of the eclipsing binary GR Bootis

• We present time-series CCD photometry and low-resolution spectra for the eclipsing binary GR Boo.
• We analyze the variations of the orbital period and determine a new ephemeris formula.
• We firstly perform photometric analysis of GR Boo using the W-D program.
• The evolutionary status and physical nature of GR Boo are briefly discussed.

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 dP/dt=−2.05×10−10ddP/dt=−2.05×10−10dyr−1yr−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±0.001q=0.985±0.001. The evolutionary status and physical nature of the binary system are briefly discussed.