---
title: "From planet catalogs to populations"
description: "Derive survey selection and planet occurrence, replay a fixed DR25 sample, and read the primary radius-valley and architecture evidence."
canonical_url: "https://sandboxphysics.com/stories/planet-populations/"
language: "en"
page_type: "story"
alternate_languages:
  zh-CN: "https://sandboxphysics.com/zh/stories/planet-populations/"
last_modified: "2026-11-03"
---

AC24

# From planet catalogs to populations

Sandbox Physics · 2026-11-03

Follow a small shadow through a noisy search. Keep the stars with no discoveries, then ask what the surviving catalog tells you about planets.

1. L1

   ## [Why do large planets fill a discovery catalog?](https://sandboxphysics.com/stories/planet-populations/why-big-planets-fill-the-catalog/)

   Planet catalogs favour signals a search can find. Follow transit geometry, observing gaps and noise to separate discoveries from the true population.

2. L1

   ## [Keep the stars with no detected planet](https://sandboxphysics.com/stories/planet-populations/keep-stars-without-detections/)

   Transit geometry and every searched star set planet occurrence. Derive alignment and distinguish planet counts from host fractions.

3. L2

   ## [Which transits survive the survey?](https://sandboxphysics.com/stories/planet-populations/which-transits-survive/)

   Transit recovery depends on finite exposures, orbital alignment and observing windows. Derive a Gaussian test and combine the probabilities consistently.

4. L3

   ## [From a few detections to a population](https://sandboxphysics.com/stories/planet-populations/from-counts-to-a-population/)

   Planet occurrence needs an integer catalog and effective search exposure. Derive its posterior and track classification, selection and radius errors.

5. L3

   ## [Replay a bounded DR25 parent sample](https://sandboxphysics.com/stories/planet-populations/replay-a-dr25-parent-sample/)

   Kepler DR25 occurrence can be rerun from fixed source bytes. Rebuild the searched-star sample and propagate unmeasured selection into rate bounds.

6. L4

   ## [Read the evidence for the radius valley](https://sandboxphysics.com/stories/planet-populations/read-radius-valley-evidence/)

   Radius-valley figures combine selected samples, radius errors and physical models. Read fixed CKS, host-mass and planetary-architecture evidence.

[Turn the detector dial and compare the population](https://sandboxphysics.com/labs/planet-survey-selection/)

## Sources and calculation scope

1. [NASA Exoplanet Archive DR25 completeness/reliability and simulated products](https://exoplanetarchive.ipac.caltech.edu/docs/Kepler_completeness_reliability.html)

   Official DR25 product roles and the INJ1 source tables.

2. [Christiansen 2017, Pixel-Level Transit Injection Tests of Pipeline Detection Efficiency for DR25](https://exoplanetarchive.ipac.caltech.edu/docs/KSCI-19110-001.pdf)

   KSCI-19110-001, sections 2–4 and pp. 9–12: ephemeris matching, aperture-corrected depth, expected MES and original table columns.

3. [Burke and Catanzarite 2017, Per-Target Detection Contours for DR25](https://exoplanetarchive.ipac.caltech.edu/docs/KSCI-19111-002.pdf)

   KSCI-19111-002, Equations 1–2, sections 3.5–3.6 and 4–7: OSD, windows and target-dependent transfer.

4. [Coughlin, Robovetter Completeness and Effectiveness for DR25](https://exoplanetarchive.ipac.caltech.edu/docs/KSCI-19114-002.pdf)

   KSCI-19114-002: injected, inverted and scrambled products; Robovetter dispositions and reliability.

5. [Measuring Transit Signal Recovery in the Kepler Pipeline IV](https://arxiv.org/html/2010.04796v1)

   Version 2010.04796v1, sections II–IV: pixel-injection design and pooled recovery response.

6. [A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence Rates](https://arxiv.org/html/1906.03575v4)

   Version 1906.03575v4, sections II–VI, Equations 10–12 and Appendix B: externally weighted integer catalogs and occurrence likelihoods.

7. [Reliability Correction is Key for Robust Kepler Occurrence Rates](https://arxiv.org/html/2006.15719v1)

   Version 2006.15719v1, sections II–III and Figures 4–5: classification reliability, scores and catalog sensitivity.

8. [The California-Kepler Survey III. A Gap in the Radius Distribution of Small Planets](https://arxiv.org/html/1703.10375v2)

   Version 1703.10375v2, Figure 7, sections II–V and Appendix C: selected CKS population, weighted radius distribution and synthetic checks.

9. [Shallower radius valley around low-mass hosts](https://arxiv.org/html/2401.12378v2)

   Version 2401.12378v2, Equations 1–6, Figures 4–8 and section 3.3: normalized valley contrast, host dependence and radius-cell migration.

10. [About 30 percent of Sun-like Stars Have Kepler-like Planetary Systems](https://arxiv.org/html/1802.09526v2)

    Version 1802.09526v2, section III.1, Equations 1–4, sections III.4–III.5 and Figures 7–9: planets per star, host fraction and system architecture.

11. [IAU 2015 Resolution B3 nominal conversion constants](https://arxiv.org/html/1510.07674v1)

    IAU 2015 Resolution B3 conversion constants, version 1510.07674v1.

12. [NASA Exoplanet Archive reuse and acknowledgment guidance](https://exoplanetarchive.ipac.caltech.edu/docs/faq.html)

    NASA Exoplanet Archive reuse and original-source acknowledgments.