Physical Sciences and Mathematics Commons^™

Whole Earth Telescope Discovery Of A Strongly Distorted Quadrupole Pulsation In The Largest Amplitude Rapidly Oscillating Ap Star, Daniel L. Holdsworth, Donald W. Kurtz, Hideyuki Saio, Judith L. Provençal, Bruno Letarte, Ramotholo R. Sefako, Véronique Petit, Barry Smalley, H. Thomsen, C. L. Fletcher

Aerospace, Physics, and Space Science Faculty Publications

We present a new analysis of the rapidly oscillating Ap (roAp) star, 2MASS J19400781 - 4420093 (J1940; V = 13.1). The star was discovered using SuperWASP broad-band photometry to have a frequency of 176.39 d-1 (2041.55 μHz; P = 8.2min; Holdsworth et al. 2014a) and is shown here to have a peak-to-peak amplitude of 34 mmag. J1940 has been observed during three seasons at the South African Astronomical Observatory, and has been the target of a Whole Earth Telescope campaign. The observations reveal that J1940 pulsates in a distorted quadrupole mode with unusual pulsational phase variations. A higher signal-to-noise ratio …