The TAOS Project Stellar Variability I. Detection of Low-Amplitude delta Scuti Stars

TL;DR

This study utilized TAOS data to identify 41 low-amplitude delta Scuti stars with short periods, demonstrating the effectiveness of FFT in detecting small-amplitude, short-period stellar variability.

Contribution

First detection of low-amplitude delta Scuti stars using high-cadence TAOS data with FFT analysis, expanding methods for identifying short-period stellar variables.

Findings

Identified 41 low-amplitude delta Scuti stars.

Detected periods around one hour.

Amplitudes smaller than a few hundredths of a magnitude.

Abstract

We analyzed data accumulated during 2005 and 2006 by the Taiwan-American Occultation Survey (TAOS) in order to detect short-period variable stars (periods of <~ 1 hour) such as delta Scuti. TAOS is designed for the detection of stellar occultation by small-size Kuiper Belt Objects (KBOs) and is operating four 50cm telescopes at an effective cadence of 5Hz. The four telescopes simultaneously monitor the same patch of the sky in order to reduce false positives. To detect short-period variables, we used the Fast Fourier Transform algorithm (FFT) inasmuch as the data points in TAOS light-curves are evenly spaced. Using FFT, we found 41 short-period variables with amplitudes smaller than a few hundredths of a magnitude and periods of about an hour, which suggest that they are low-amplitude delta Scuti stars (LADS). The light-curves of TAOS delta Scuti stars are accessible online at the Time Series Center website (http://timemachine.iic.harvard.edu)