Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2609.37517

The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey

Arkaprova Dutta·Priyanka Chaturvedi
View original source ↗Read source document ↗Export metadata ↓

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 work, we present a uniform analysis of planet occurrence around a sample of 282,904 subgiant stars selected from the Gaia DR3 catalogue. We perform an independent reanalysis of TESS light curves for transit-signal detection and refinement, followed by multi-stage vetting including visual inspection and statistical false-positive assessment. We quantify 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_earth range and a secondary enhancement at 12-15 R_earth. These results provide a demographic baseline for studying the population of close-in planets around stars undergoing early post-main-sequence evolution.

Explore related subjects

astro-ph.EPastro-ph.SR

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Arkaprova Dutta, Priyanka Chaturvedi. 2026-09-29. The Occurrence Rate of Planets Around Subgiant Stars from TESS Photometric Survey. https://arxiv.org/abs/2609.37517

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

A Comparative Study of the Streaming Instability: Unstratified Models with Marginally Coupled Grains

The streaming instability is a leading mechanism for concentrating solids and initiating planetesimal formation in protoplanetary disks. Although numerous studies have explored its linear growth, nonlinear evolution, and implications for planet formation, the diversity of numerical methods and dust treatments used across the literature has made it difficult to assess which features of the instability are physically robust and which arise from code-dependent choices. We present the first systematic comparison of seven hydrodynamic codes--spanning finite-volume and finite-difference schemes and modeling dust either as Lagrangian particles or as a pressureless fluid--applied to the unstratified streaming instability with a dimensionless stopping time of unity. All codes reproduce the characteristic sequence of exponential growth, filament formation, and turbulent saturation, demonstrating broad agreement in the qualitative behavior of the instability. Quantitatively, however, the dust model remains the dominant source of variation at moderate resolution: particle-based simulations reach higher peak densities and exhibit broader high-density tails than fluid-based models at $512^2$ resolution, although increasing the number of particles brings their initial maximum density evolution into close agreement with that of dust-fluid models. At $1024^2$, these differences diminish substantially, indicating better agreement of the saturated-state statistics across dust treatments. In terms of computational performance, most particle implementations suffer from imbalanced parallelized loads, while execution on a GPU is at least two to three times more energy efficient and scales better at higher resolutions than on CPUs. Given the intrinsic stochasticity of this nonlinear system, only statistical diagnostics remain meaningful across codes.

astro-ph.EP↗
arXiv2026

Hydrodynamic escape from the proto-lunar disk and the origin of the Earth-Moon volatile dichotomy

Volatile elements - those that vaporize at low temperatures - are depleted in lunar rocks relative to terrestrial rocks. This systematic chemical depletion is evidence for vaporization and preferential removal of vapor from proto-lunar materials during the high-temperature processes accompanying lunar origin. Despite the robustness of these observations, the physical processes by which proto-lunar vapors were removed after the giant impact are not yet well-understood. Here, we show that toward the end of post-giant impact cooling history, Earth's atmosphere was dominated by carbon species (e.g., CO) and was spatially compact, behaving as a closed system retaining Earth's volatile inventory, whereas the proto-lunar disk atmosphere was dominated by H and H2 and was spatially extended, developing into a hydrodynamic outflow analogous to the solar wind. We find that equilibrium H2 recombination (2H->H2) in a partially-dissociated disk atmosphere produces a nearly isothermal structure, a feature known to activate outflows. The expected outflow was strong enough to propel proto-lunar volatiles from a Roche-interior (r < 3RE) disk out of Earth's gravity field and to establish a cometary tail composed of volatile elements transporting proto-lunar disk volatiles into interplanetary space. The proposed model suggests that the dichotomy in volatile element abundances between the silicate Earth and Moon is a natural outcome of the hydrodynamical behavior of magma ocean atmospheres and that lunar chemical and isotopic volatile abundances are diagnostic of the radial structure of the proto-lunar disk towards the end of its condensation.

astro-ph.EP↗
arXiv2026

Pulsed Accretion onto Eccentric Binaries in Highly Misaligned Circumbinary Disks

We present three-dimensional smoothed particle hydrodynamics simulations of highly misaligned circumbinary disks (CBDs) around moderately eccentric equal-mass binaries ($e_\mathrm{b}=0.5$). We show that the binary accretion is modulated on the binary orbital period and exhibits two pulses near periastron. The dominant pulse peaks before periastron for an initial binary-disk misalignment of $60^\circ$, shifts to after periastron at $90^\circ$, and occurs at an even later post-periastron phase at $120^\circ$. We further show that the two pulses are accompanied by a time-dependent response of the circumstellar disks (CSDs) and by different distributions of accreting material within the cavity and around the CSDs. The qualitative pre- versus post-periastron distinction is also present in individual binary orbits despite variations in pulse amplitude. Our results motivate future tests of whether pulse timing is related to binary-disk orientation.

astro-ph.EP↗