1999A&A...345..553W

We present a period analysis of the two early-type and well-known eccentric eclipsing binaries RU Mon (P=3.58d, e=0.45) and DR Vul (P=2.25d, e=0.10). Several new times of minimum light recorded with photoelectric means have been gathered. The O-C diagrams are analyzed using all reliable timings found in the literature and new values for the elements of the apsidal motion and light-time effect are computed. We confirmed the very short period of apsidal motion of about 36.3 years for DR Vul. The third bodies have an orbital period of about 73 and 63 years for RU Mon and DR Vul, respectively.