CCD Photometry, Light Curve Deconvolution, Period Analysis, and Evolutionary Status of the HADS Variable V1116 Herculis

Volume 51 number 2 (2023)

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W. Allen Gilchrist, Jr.

Stonecrest Observatory, 104 Deer Ridge Drive, Fort Davis, TX 79734; gilchrist.allen@ymail.com

Kevin B. Alton

UnderOak and Desert Blooms Observatories, 70 Summit Avenue, Cedar Knolls, NJ; kbalton@optonline.net

Abstract

CCD-derived photometric B-, V-, Rc-, and Ic-magnitude data were acquired for V1116 Her, an intrinsic pulsating variable classified as a High Amplitude δ Scuti (HADS) star. Precise time-series light curve data were deconvolved using discrete Fourier transformation, revealing a fundamental mode (f0) of oscillation at 10.5610 d–1 along with at least three other partial harmonics (2f0—4f0). At least nine other statistically significant frequencies were resolved following successive pre-whitening of each residual signal. An assessment of potential period changes over time was performed using 46 new times of maximum (ToMx) light produced from the present study (2022) along with 160 other ToMx values extracted from the TESS survey earlier in 2022. These results indicate that no substantive change in the fundamental period of oscillation or amplitude (nominally Ic-mag) has likely occurred over the past two years. Finally, an investigation with PARSEC models for generating stellar tracks and isochrones provided a better understanding about the evolutionary status of this star.