Refining Ephemeris and Estimating Period Change Rate for V965 Cephei

Volume 49 number 1 (2021)

Download this article (pdf)

Maksym Pyatnytskyy

Dzhona Makkeina 37, apt. 6, Kyiv, 01042, Ukraine; mpyat2@gmail.com

Abstract

Using observations from the AAVSO International Database, data from the literature, and new photometry from the current investigation, the author has produced an O–C diagram for the HADS star V965 Cephei for the time interval September 2011 through December 2020. Analysis of the O–C diagram revealed that V965 Cep has been increasing its period at a constant rate (1 / P) (dP / dt) of 1.02 (8) × 10–6 yr–1. A refined ephemeris for the star: Tmax (HJD) = 2457504.8963(2) + 0.085067421(9) E + 1.01(8) × 10–11 E2.