The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey
Abstract
Subgiant stars represent a critical phase in stellar evolution, offering an opportunity to investigate how planetary systems respond to the early stages of post-main-sequence expansion. Despite their importance, systematic occurrence-rate studies of this population remain sparse compared with those of main-sequence and red-giant hosts. In this paper, we present a uniform analysis of planet occurrence around a sample of 282,904 subgiant stars selected from the \textit{Gaia} Data Release 3 (DR3) catalogue. We performed an independent re-analysis of Transiting Exoplanet Survey Satellite (TESS) light curves for transit-signal detection and refinement, followed by multi-stage vetting including a visual inspection and statistical false-positive assessment. We quantified the detection sensitivity of the survey through injection-and-recovery experiments, with 565,808 synthetic transit signals injected across the stellar sample. Over the period range of 1--10 days and the planet-radius range for which the detection completeness is well characterised, we measure a completeness-corrected planet occurrence rate of 0.644+0.048−0.041%. The occurrence rate is strongly dependent on planet radius, with the highest occurrence contributed by planets in the $1−−4\,R_{\oplus}$ range and a secondary enhancement at $12−−15\,R_{\oplus}$. These results provide a demographic baseline for studying the population of close-in planets around stars undergoing early post-main-sequence evolution.
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BibTeX
@misc{dutta2026occurrence,
title = {{The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey}},
author = {Arkaprova Dutta and Priyanka Chaturvedi},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.37517},
eprint = {2609.37517},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.37517},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey
AU - Arkaprova Dutta
AU - Priyanka Chaturvedi
PY - 2026
DA - 2026/10/27
PB - arXiv
DO - 10.48550/arxiv.2609.37517
UR - https://arxiv.org/abs/2609.37517
AB - Subgiant stars represent a critical phase in stellar evolution, offering an opportunity to investigate how planetary systems respond to the early stages of post-main-sequence expansion. Despite their importance, systematic occurrence-rate studies of this population remain sparse compared with those of main-sequence and red-giant hosts. In this paper, we present a uniform analysis of planet occurrence around a sample of 282,904 subgiant stars selected from the \textit{Gaia} Data Release 3 (DR3) catalogue. We performed an independent re-analysis of Transiting Exoplanet Survey Satellite (TESS) light curves for transit-signal detection and refinement, followed by multi-stage vetting including a visual inspection and statistical false-positive assessment. We quantified the detection sensitivity of the survey through injection-and-recovery experiments, with 565,808 synthetic transit signals injected across the stellar sample. Over the period range of 1--10 days and the planet-radius range for which the detection completeness is well characterised, we measure a completeness-corrected planet occurrence rate of 0.644^+0.048_−0.041%. The occurrence rate is strongly dependent on planet radius, with the highest occurrence contributed by planets in the $1−−4\,R_{\oplus}$ range and a secondary enhancement at $12−−15\,R_{\oplus}$. These results provide a demographic baseline for studying the population of close-in planets around stars undergoing early post-main-sequence evolution.
ER -