The Sensitivity of TESS to Transiting Planets in TOIs with Close-in Stellar Companions
4 affiliations
- 1Bay Area Environmental Research Institute
- 2Mount Holyoke College
- 3NASA Exoplanet Science Institute
- 4NASA Ames Research Center
Abstract
High-resolution imaging with optical speckle interferometry has revealed that many transiting exoplanet host stars possess close-in stellar companions. The objective of this study is to quantify how the presence of these companions impacts the ability of TESS to detect the transits of small planets. We accomplish this by examining 2052 TESS Objects of Interest (TOIs) that appear to be single-star systems based on speckle interferometric observations as well as 188 TOIs in unresolved (<1 . ″ 2) stellar binaries. For each planet, we take its transit signal-to-noise ratio (SNR), radius, and orbital period from the TOI catalog and, for planets in stellar binaries, we correct the radius for dilution by the companion. By applying a scaling relation to the measured transit SNR of each TOI in our sample, we determine the detectability of transits in each TOI as a function of both planet radius and orbital period. When applied to the full sample, this procedure elucidates the sensitivity of TESS to transiting planets as a function of binarity, host-star spectral type, planet radius, and planet orbital period. These sensitivity grids quantify the bias against the detection of small planets in unresolved binaries by TESS and show that there is a particularly low sensitivity to planets transiting secondary stars in unresolved binaries, especially as the magnitude difference between the stars increases. These sensitivity grids are available for download to facilitate their use in other studies.
Related
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BibTeX
@article{littlefield2026sensitivity,
title = {{The Sensitivity of TESS to Transiting Planets in TOIs with Close-in Stellar Companions}},
author = {Colin Littlefield and Kathryn V. Lester and David R. Ciardi and Steve B. Howell},
journal = {The Astronomical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-3881/aea57d},
url = {https://iopscience.iop.org/article/10.3847/1538-3881/aea57d},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The Sensitivity of TESS to Transiting Planets in TOIs with Close-in Stellar Companions
AU - Colin Littlefield
AU - Kathryn V. Lester
AU - David R. Ciardi
AU - Steve B. Howell
PY - 2026
DA - 2026/10/21
JO - The Astronomical Journal
DO - 10.3847/1538-3881/aea57d
UR - https://iopscience.iop.org/article/10.3847/1538-3881/aea57d
AB - High-resolution imaging with optical speckle interferometry has revealed that many transiting exoplanet host stars possess close-in stellar companions. The objective of this study is to quantify how the presence of these companions impacts the ability of TESS to detect the transits of small planets. We accomplish this by examining 2052 TESS Objects of Interest (TOIs) that appear to be single-star systems based on speckle interferometric observations as well as 188 TOIs in unresolved (<1 . ″ 2) stellar binaries. For each planet, we take its transit signal-to-noise ratio (SNR), radius, and orbital period from the TOI catalog and, for planets in stellar binaries, we correct the radius for dilution by the companion. By applying a scaling relation to the measured transit SNR of each TOI in our sample, we determine the detectability of transits in each TOI as a function of both planet radius and orbital period. When applied to the full sample, this procedure elucidates the sensitivity of TESS to transiting planets as a function of binarity, host-star spectral type, planet radius, and planet orbital period. These sensitivity grids quantify the bias against the detection of small planets in unresolved binaries by TESS and show that there is a particularly low sensitivity to planets transiting secondary stars in unresolved binaries, especially as the magnitude difference between the stars increases. These sensitivity grids are available for download to facilitate their use in other studies.
SN - 0004-6256
SN - 1538-3881
ER -