산개성단 NGC 6871을 중심으로 한 Cyg OB3 성협 영역의 변광성 I: δ Scuti 형 변광성

Abstract

As a part of the short-period variability survey (SPVS) at Bohyunsan Optical Astronomy Observatory, we obtained time-series BV CCD images in the region of Cyg OB3 association centered on the open cluster NGC 6871. The observations were performed for 18 nights from September 5, 2008 to September 1, 2009. We found 15 short-period variable stars in the region. They are Scuti type stars belonging to the local spiral arm, Orion spur. Among them, only two stars were previously known, and the rest are newly discovered ones. In this paper, we have performed a multiple-frequency analysis to determine frequencies of the 15 Scuti type stars, using the discrete Fourier transform and linear least-square fitting methods. One of the newly discovered variable stars is a double-mode Scuti type star with the fundamental and the first overtone modes, and two are high amplitude Scuti stars.