TESS-Gaia Light Curve: a PSF-based TESS FFI light curve product

TL;DR

This paper introduces TGLC, a high-precision, PSF-based light curve product from TESS FFI data using Gaia priors, enabling detailed analysis of stars beyond pre-selected targets.

Contribution

The paper presents a novel PSF-based method for extracting high-precision light curves from TESS FFI data using Gaia DR3 positions and magnitudes, improving photometric accuracy in crowded fields.

Findings

Photometric precision reaches <~2% at 16th TESS magnitude.

TGLC light curves closely match pre-launch noise predictions.

Open-source package tglc enables customized light curve production.

Abstract

The Transiting Exoplanet Survey Satellite (TESS) is continuing its second extended mission after 55 sectors of observations. TESS publishes full-frame images (FFI) at a cadence of 1800, 600, or 200 seconds, allowing light curves to be extracted for stars beyond a limited number of pre-selected stars. Simulations show that thousands of exoplanets, eclipsing binaries, variable stars, and other astrophysical transients can be found in these FFI light curves. To obtain high-precision light curves, we forward model the FFI with the effective point spread function to remove contamination from nearby stars. We adopt star positions and magnitudes from Gaia DR3 as priors. The resulting light curves, called TESS-Gaia Light Curves (TGLC), show a photometric precision closely tracking the pre-launch prediction of the noise level. TGLC's photometric precision reaches <~2% at 16th TESS magnitude even in crowded fields. We publish TGLC Aperture and PSF light curves for stars down to 16th TESS magnitude through the Mikulski Archive for Space Telescopes (MAST) for all available sectors and will continue to deliver future light curves via DOI: 10.17909/610m-9474. The open-source package tglc is publicly available to enable any user to produce customized light curves.