Searching for TESS Photometric Variability of Possible JWST Spectrophotometric Standard Stars

Abstract

We use data from the Transiting Exoplanet Survey Satellite (TESS) to search for, and set limits on, optical to near-infrared photometric variability of the well-vetted, candidate James Webb Space Telescope (JWST) spectrophotometric standards. Our search of 37 of these candidate standards has revealed measurable periodic variability in 15 stars. The majority of those show variability that is less than half a percent; however, four stars are observed to vary photometrically, from minimum to maximum flux, by more than 1% (the G dwarf HD 38949 and three fainter A dwarfs). Variability of this size would likely impact the error budget in the spectrophotometric calibration of the science instruments aboard JWST. For the 22 candidate standards with no detected variability, we report upper limits on the observed changes in flux. Despite some systematic noise, all stars brighter than 12 magnitude in the TESS band show a 3 sigma upper limit on the total change in brightness of less than half a percent on time scales between an hour and multiple weeks, empirically establishing their suitability as spectrophotometric standards. We further discuss the value and limits of high-cadence, high-precision photometric monitoring with TESS as a tool to vet the suitability of stars to act as spectrophotometric standards.

17 pages, 5 figures, 3 tables, accepted for publication by AAS Journals

References in corpus (14)

• The Transiting Exoplanet Survey Satellite
• The James Webb Space Telescope
• Techniques and Review of Absolute Flux Calibration from the Ultraviolet to the Mid-Infrared
• TESS Eclipsing Binary Stars. I. Short cadence observations of 4584 eclipsing binaries in Sectors 1-26
• Asteroseismology of the solar analogs 16 Cyg A & B from Kepler observations
• Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars
• A dusty veil shading Betelgeuse during its Great Dimming
• The Gaia spectrophotometric standard stars survey - III. Short-term variability monitoring
• Spectral Calibration in the Mid-Infrared: Challenges and Solutions
• An accreting white dwarf displaying fast transitional mode switching
• The Gaia spectrophotometric standard stars survey -- IV. Results of the absolute photometry campaign
• Spitzer IRAC observations of JWST calibration stars
• Identifying Candidate Optical Variables Using Gaia Data Release 2
• TESS Photometric Mapping of a Terrestrial Planet in the Habitable Zone: Detection of Clouds, Oceans, and Continents

Cited by in corpus (6)

• The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope -- III. Single Object Slitless Spectroscopy
• Localizing Sources of Variability in Crowded TESS Photometry
• Astrometric Gravitational-Wave Detection via Stellar Interferometry
• How do Spitzer IRAC Fluxes Compare to HST CALSPEC
• Pulsation in TESS Objects of Interest
• Analysing the flux stability of stellar calibrator candidates with TESS