TESS Data for Asteroseismology: Timing verification

Abstract

The Transiting Exoplanet Survey Satellite (TESS) is NASA's latest space telescope dedicated to the discovery of transiting exoplanets around nearby stars. Besides the main goal of the mission, asteroseismology is an important secondary goal and very relevant for the high-quality time series that TESS will make during its two year all-sky survey. Using TESS for asteroseismology introduces strong timing requirements, especially for coherent oscillators. Although the internal clock on board TESS is precise in its own time, it might have a constant drift and will thus need calibration, or offsets might inadvertently be introduced. Here we present simultaneously ground- and space-based observations of primary eclipses of several binary systems in the Southern ecliptic hemisphere, used to verify the reliability of the TESS timestamps. From twelve contemporaneous TESS/ground observations we determined a time offset equal to 5.8 +/- 2.5 sec, in the sense that the Barycentric time measured by TESS is ahead of real time. The offset is consistent with zero at 2.3-sigma level. In addition, we used 405 individually measured mid-eclipse times of 26 eclipsing binary stars observed solely by TESS to test the existence of a potential drift with a monotonic growth (or decay) affecting the observations of all stars. We find a drift corresponding to sigma_drift = 0.009 +/- 0.015 sec/day. We find that the measured offset is of a size that will not become an issue for comparing ground-based and space data for coherent oscillations for most of the targets observed with TESS.

15 pages, 9 figures

References in corpus (19)

• The Transiting Exoplanet Survey Satellite
• The K2 Mission: Characterization and Early results
• Kepler Mission Design, Realized Photometric Performance, and Early Science
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• The CoRoT satellite in flight : description and performance
• The effect of red noise on planetary transit detection
• The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives
• Parameter Estimation from Time-Series Data with Correlated Errors: A Wavelet-Based Method and its Application to Transit Light Curves
• Hot super-Earths stripped by their host stars
• High-precision photometry by telescope defocussing. I. The transiting planetary system WASP-5
• Asteroseismic determination of obliquities of the exoplanet systems Kepler-50 and Kepler-65
• Giant star seismology
• Asteroseismology of solar-type stars
• What asteroseismology can do for exoplanets: Kepler-410A b is a Small Neptune around a bright star, in an eccentric orbit consistent with low obliquity
• An Eccentric Massive Jupiter Orbiting a Sub-Giant on a 9.5 Day Period Discovered in the Transiting Exoplanet Survey Satellite Full Frame Images
• TESS exoplanet candidates validated with HARPS archival data. A massive Neptune around GJ143 and two Neptunes around HD23472
• Qatar-1: indications for possible transit timing variations
• Data preparation for asteroseismology with TESS
• Kepler Object of Interest Network I. First results combining ground and space-based observations of Kepler systems with transit timing variations

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