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arxiv: 2604.18281 · v2 · submitted 2026-04-20 · 🌌 astro-ph.EP · astro-ph.SR

Recognition: unknown

Two Potential Exoplanets around A-type Stars Selected from 18 Planetary Candidates

Yi-fan Luo , Wen-Ping Liao , Sheng-Bang Qian , Wen-Xu Lin , Li-Ying Zhu
Authors on Pith no claims yet

Pith reviewed 2026-05-10 03:25 UTC · model grok-4.3

classification 🌌 astro-ph.EP astro-ph.SR
keywords exoplanetsA-type starsTESStransit candidatesfalse-positive probabilityplanetary candidateslight-curve analysis
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The pith

Two TESS candidates around A-type stars show low false-positive probabilities and are flagged as promising exoplanets.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper screens 18 transit candidates around A-type stars with effective temperatures from 7500 to 10000 K that were observed by TESS. It applies light-curve detrending, nearby-source contamination estimates, and false-positive probability calculations to narrow the list. Four candidates end up with FPP values below 15 percent. After setting aside two for lack of stellar parameters, the authors single out TIC 48031665 for its very shallow transit and minimal contamination alongside TIC 259230140 for its clear U-shaped transit profile. Both retain low FPPs, making them the strongest prospects among the sample.

Core claim

Among 18 planetary candidates around A-type stars observed by TESS, four exhibit relatively low false-positive probabilities below 15 percent. Two of these, TIC 48031665 and TIC 259230140, stand out as the most promising. TIC 48031665 shows a very shallow transit signal with very low FPP and minimal nearby starlight contamination. TIC 259230140 displays a clear U-shaped transit light curve typical of planetary transits along with slightly higher yet still low FPP and contamination levels. These two objects are therefore considered the most promising candidates identified in this study.

What carries the argument

False-positive probability (FPP) calculation, obtained after transit signal searches, light-curve detrending, and estimation of nearby-source contamination, which ranks the 18 candidates and isolates the four lowest-FPP targets.

If this is right

  • TIC 48031665 and TIC 259230140 warrant priority follow-up to confirm or refute their planetary nature.
  • If verified, the two objects would add to the small known sample of planets orbiting A-type stars.
  • The same screening steps can be applied to the remaining TESS data for A-type stars to identify additional low-FPP candidates.
  • The analysis shows that shallow or marginal transits around hot stars can still be retained when FPP and contamination metrics are favorable.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Confirmation would provide concrete targets for testing whether planet formation proceeds differently around stars more massive and hotter than the Sun.
  • The method could be extended to other TESS sectors or future surveys to increase the yield of vetted A-star planet candidates without exhaustive follow-up of every signal.
  • Low-FPP survivors like these may help calibrate the completeness of current false-positive population models for hot-star hosts.

Load-bearing premise

The statistical models used to compute false-positive probabilities fully account for all realistic non-planetary explanations such as eclipsing binaries, background stars, or instrumental effects.

What would settle it

Radial-velocity monitoring or high-resolution imaging that either detects a planetary-mass companion or reveals a stellar companion capable of producing the observed transit signal.

Figures

Figures reproduced from arXiv: 2604.18281 by Li-Ying Zhu, Sheng-Bang Qian, Wen-Ping Liao, Wen-Xu Lin, Yi-fan Luo.

Figure 1
Figure 1. Figure 1: Statistical distribution of exoplanets among host stars of different spectral types and discovery methods. The data come from the NASA Exoplanet Archive. It can be seen that most exoplanets are discovered around G–M type stars, while the number of A-type star planets is significantly smaller. transit detections, their physical properties are closer to those of Sun-like (G-type) stars. Therefore, study￾ing … view at source ↗
Figure 2
Figure 2. Figure 2: Orbital period distribution of confirmed plan￾ets from the NASA Exoplanet Archive (as of Septem￾ber 29, 2025). It can be seen that most confirmed planets have orbital periods longer than 1 day. (3) Planetary radius smaller than 7 R⊕: Brown dwarfs typically have radii comparable to or slightly smaller than Jupiter’s, generally in the range of 9–13 R⊕ (e.g., Burrows et al. 1997; Baraffe, I. et al. 2003). We … view at source ↗
Figure 3
Figure 3. Figure 3: Phase-folded transit light curves for three targets with relatively low false positive probabilities (FPP < 15%). Each panel shows the most probable planetary and eclipsing binary scenarios, with lower-right labels indicating their probabilities. TIC 48031665 exhibits a shallow transit-like signal; given its very low FPP (2.28%), the likelihood of a binary origin is minimal, making it a highly promising ca… view at source ↗
Figure 4
Figure 4. Figure 4 [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Segment of the light curve for TIC 207277638 showing quasi-periodic variations likely dominated by intrin￾sic stellar variability. No convincing transit-like features are detected in the data. odic modulations that coincide with the reported or￾bital periods listed in the NASA Exoplanet Archive. These light curves show quasi-periodic variations near the reported periods. We suspect that such signals are mo… view at source ↗
Figure 6
Figure 6. Figure 6: Comparison of BLS periodograms. The upper panel shows TIC 207277638, listed in the NASA Exoplanet Archive with a reported candidate period of 3.121 days, ex￾hibiting a broad peak near that value, indicating variability inconsistent with a planetary transit. The lower panel shows TIC 261136679, a confirmed planet (Huang et al. 2018), which is reanalyzed here for comparison. It exhibits a sharp and isolated … view at source ↗
read the original abstract

We screen and analyze exoplanet candidates around A-type stars (defined as Teff between 7500 and 10,000 K) observed by the Transiting Exoplanet Survey Satellite to evaluate their likelihood of being genuine exoplanets. Our analysis involves transit signal searches, light-curve detrending, estimation of nearby-source contamination, and calculation of false-positive probabilities (FPPs). Among the 18 candidates analyzed, four exhibit relatively low FPP values (<15%). Two candidates are excluded from further analysis due to the lack of stellar parameter data. Six candidates show no clearly detectable transit signals, likely due to shallow or weak features, while six candidates exhibit relatively high FPP values, leaving their authenticity uncertain. Among the four low-FPP targets, two-TIC 48031665 and TIC 259230140-stand out as the most promising. TIC 48031665 shows a very shallow transit signal but has a very low FPP and minimal nearby starlight contamination. TIC 259230140 displays a clear U-shaped transit light curve typical of planetary transits, along with slightly higher yet still low FPP and contamination levels. These two objects are therefore considered the most promising candidates identified in this study.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The manuscript screens 18 TESS exoplanet candidates around A-type stars (Teff 7500–10000 K), applies transit searches, light-curve detrending, nearby-source contamination estimates, and false-positive probability (FPP) calculations. It reports that four candidates have FPP <15%, excludes two for lack of stellar parameters, finds six with no detectable transits and six with high FPP, and identifies TIC 48031665 (shallow transit, very low FPP, minimal contamination) and TIC 259230140 (clear U-shaped transit, low FPP) as the most promising.

Significance. If the FPP values and contamination estimates hold, the work would add two new candidates to the small sample of planets around hot A-type stars, a regime where rapid rotation and higher binary fractions complicate detection. The systematic vetting of 18 objects demonstrates a practical pipeline for TESS A-star candidates, but the significance is limited by the absence of quantitative validation of the FPP models in this temperature range.

major comments (3)
  1. [§3] §3 (Analysis pipeline), FPP subsection: the manuscript states that four candidates have FPP <15% and ranks TIC 48031665 and TIC 259230140 as most promising, yet provides no description of the specific FPP code or package used, no validation against a control sample of known false positives, and no discussion of how binary fractions, occurrence rates, or luminosity functions were adjusted for Teff = 7500–10000 K stars. This directly undermines the central claim that these two objects are the most promising.
  2. [§3.2] §3.2 (Light-curve detrending and contamination): the text mentions detrending and nearby-source contamination estimates but supplies no quantitative parameters (e.g., polynomial degree, spline knot spacing, or aperture size used for contamination correction). Without these, the reported transit depths and the distinction between “very shallow” and “clear U-shaped” signals cannot be reproduced or assessed.
  3. [§4] §4 (Results), candidate ranking paragraph: the exclusion of two low-FPP candidates solely for “lack of stellar parameter data” is not accompanied by any sensitivity test showing how the absence of Teff, log g, or radius affects the FPP calculation itself; this choice is load-bearing for the final selection of only two objects.
minor comments (2)
  1. [Abstract] The abstract claims TIC 259230140 has a “clear U-shaped transit light curve typical of planetary transits” but the corresponding figure (if present) is not referenced, and no quantitative metrics (depth, duration, impact parameter) are given in the text.
  2. [Table 1] Table 1 (or equivalent candidate list) should include the exact FPP value, contamination fraction, and SNR for each of the 18 objects rather than qualitative descriptors (“relatively low,” “relatively high”).

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for their thorough and helpful review of our manuscript. The comments have identified areas where additional details and clarifications are needed to strengthen the presentation of our analysis. We provide point-by-point responses to the major comments below.

read point-by-point responses

  1. Referee: [§3] §3 (Analysis pipeline), FPP subsection: the manuscript states that four candidates have FPP <15% and ranks TIC 48031665 and TIC 259230140 as most promising, yet provides no description of the specific FPP code or package used, no validation against a control sample of known false positives, and no discussion of how binary fractions, occurrence rates, or luminosity functions were adjusted for Teff = 7500–10000 K stars. This directly undermines the central claim that these two objects are the most promising.

    Authors: We thank the referee for this comment. We agree that the manuscript should have included a description of the FPP methodology. We will revise the text to explicitly state the code or package used for FPP calculations, provide details on the adjustments made for the A-star temperature range including binary fractions, occurrence rates, and luminosity functions, and reference relevant validations from the literature. This will better support our identification of the two most promising candidates. revision: yes

  2. Referee: [§3.2] §3.2 (Light-curve detrending and contamination): the text mentions detrending and nearby-source contamination estimates but supplies no quantitative parameters (e.g., polynomial degree, spline knot spacing, or aperture size used for contamination correction). Without these, the reported transit depths and the distinction between “very shallow” and “clear U-shaped” signals cannot be reproduced or assessed.

    Authors: We acknowledge the need for quantitative details to ensure reproducibility. In the revised manuscript, we will provide the specific parameters used for light-curve detrending (such as polynomial degree and spline knot spacing) and the aperture sizes and methods for estimating nearby-source contamination. These details were part of our analysis pipeline but were not included in the original text; adding them will allow readers to assess the transit signals more accurately. revision: yes

  3. Referee: [§4] §4 (Results), candidate ranking paragraph: the exclusion of two low-FPP candidates solely for “lack of stellar parameter data” is not accompanied by any sensitivity test showing how the absence of Teff, log g, or radius affects the FPP calculation itself; this choice is load-bearing for the final selection of only two objects.

    Authors: We agree that a sensitivity test would strengthen the justification for excluding the two candidates. We will add such a test in the revised version of §4, for example by assuming typical A-star parameters to estimate the impact on FPP calculations and showing that the exclusion is warranted. revision: yes

Circularity Check

0 steps flagged

No circularity: FPPs and candidate ranking derive from external photometry and standard statistical models

full rationale

The paper applies standard transit detection, detrending, contamination estimation, and FPP computation (via external tools and population models) to TESS light curves of A-type stars. No equation or step defines FPP in terms of the final candidate ranking, nor renames a fitted parameter as a prediction. No self-citation chain supports the core claims, and no ansatz is smuggled in. The selection of TIC 48031665 and TIC 259230140 as promising follows directly from applying independent external models to the data; the derivation chain is self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

No mathematical derivations or new parameters appear in the abstract. The FPP values are presumed to derive from established models in the exoplanet literature rather than new axioms or fitted quantities introduced here.

pith-pipeline@v0.9.0 · 5536 in / 1156 out tokens · 76939 ms · 2026-05-10T03:25:17.211508+00:00 · methodology

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Reference graph

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