Exoplanet Transit Analysis

ExoDip

Explore stellar light curves and screen periodic transit signals for potential exoplanet candidates.

ExoDip combines Box Least Squares period search, astrophysical feature extraction, and an ensemble of machine-learning classifiers to evaluate raw stellar photometry.

Models XGBoost · RF · CNN · SVM
Transit Search BLS 0.5 – 20 days
Features 15 astrophysical metrics
Planetary system simulation, a transiting world around its host star
What Is ExoDip?

Photometric transit screening
for candidate exoplanet signals

ExoDip processes raw stellar photometry to identify characteristic brightness dips caused when an exoplanet crosses in front of its host star along our line of sight. It is a screening engine, not a confirmation pipeline.

Why Transit Detection?

Most planets are found by watching stars, not planets

Direct imaging of exoplanets is rare. The transit method instead measures a star’s brightness over time. If a planet periodically blocks a fraction of that light, the resulting light curve encodes orbital period, transit depth, and duration.

Those signals are small, often well below 1% of the star’s flux, and sit on top of stellar variability, instrumental drift, and astrophysical false positives. That is the problem ExoDip is built to screen.

Typical Jupiter-size transit~1% dip
Typical Earth-size transit~0.01% dip
Search window0.5–20 day periods
Primary surveysKepler · TESS
How Transits Work

Why a planet creates a dip

When a planet passes between its host star and the observer, it blocks a small amount of starlight. That produces a characteristic decrease in observed brightness, the dip that gives ExoDip its name.

A planet crossing its host star and the corresponding dip in the observed stellar light curve
Planet before transit, with baseline brightness
Baseline Flux
Constant stellar brightness before the event
Planet beginning to cover the star, with brightness falling
Transit Ingress
Planet begins crossing the stellar disk; flux drops
Planet at the middle of transit, with the deepest brightness dip
Transit Mid-point
Deepest dip. Depth ≈ (Rp/R★)²
Planet leaving the star, with brightness recovering
Transit Egress
Planet exits; flux recovers to baseline
Detection Pipeline

How ExoDip works

Six automated stages from raw photometry to a calibrated candidate assessment. Technical detail lives in Documentation.

01
Light Curve Input
Upload time-series stellar flux from Kepler, TESS, or ground-based surveys in CSV, TXT, or NPY format.
02
Detrending
Filter instrumental drift, sensor artifacts, and stellar variability while preserving transit dip profiles.
03
BLS Period Search
Astropy Box Least Squares scans trial periods (0.5–20 days) to find recurring box-shaped flux dips.
04
Feature Extraction
Compute 15 astrophysical and statistical features: depth, duration, SNR, signal energy, spectral entropy, skewness.
05
ML Screening
Calibrated ensemble (XGBoost, Random Forest, CNN, SVM) evaluates the feature vector against transit-like profiles.
06
Candidate Assessment
Produce a candidate / non-candidate verdict, confidence score, diagnostic plots, and a downloadable JSON report.

Core Capabilities

What you can do with ExoDip

01

Transit Signal Detection

Identify periodic brightness dips in stellar light curves using Box Least Squares (BLS) periodogram analysis.

02

Ensemble Screening

Consensus across tuned XGBoost, Random Forest, CNN, and SVM classifiers to distinguish genuine signals from noise.

03

Light-Curve Analysis

Inspect brightness variations, transit depth, duration, and detected dip profiles with interactive diagnostic plots.

04

Candidate Insights

Review orbital period, BLS SNR, 15 astrophysical features, and export a JSON telemetry report for follow-up.

Workspace

Analyze a light curve

Upload stellar photometry and let ExoDip search for periodic transit-like signals. The full screening workspace includes upload, preprocessing, BLS, features, and ML results on a dedicated page.

Example of Analysis

What a screening result looks like

This is an illustrative example of typical outputs. It is not a live analysis from this session.

Example · Candidate

A periodic dip with sufficient BLS SNR and classifier agreement is labeled an exoplanet candidate, a recommendation for follow-up, not a confirmed planet.

Period
3.52 d
Transit Depth
1.20%
Duration
3.8 h
BLS SNR
14.8
Scientific Methodology

How the science is structured

Period search

Box Least Squares (Kovács et al. 2002) is the standard algorithm for detecting box-shaped transits in unevenly sampled photometry. ExoDip uses Astropy BLS over 0.5–20 day periods and 1–12 hour durations.

Feature vector

Fifteen morphological and statistical descriptors, including depth, duration, noise, skewness, kurtosis, signal energy, and spectral entropy, summarize the light curve for the classifiers.

Model evaluation

Ensemble models were trained and compared on Kepler photometry. XGBoost is the primary decision model based on held-out composite score (accuracy, precision–recall, and ROC-AUC).

Limitations

Screening is not confirmation

  • False positives: eclipsing binaries, grazing binaries, and blended background stars can mimic planetary transits.
  • Stellar activity: starspots, flares, and rotation can introduce spurious periodic dips.
  • Follow-up required: radial-velocity mass measurement and high-resolution imaging remain necessary for confirmation.

Documentation

Go deeper when you need the details

  1. 1. Upload
  2. 2. Configure
  3. 3. Process
  4. 4. Analyze
  5. 5. Results

Drag and drop your light-curve file here
CSV (flux column), Kepler 1-row CSV, whitespace TXT, or NPY arrays

Select an index from the held-out Kepler exoTest.csv dataset.

Range: 0 to 569
Input Specification

Data Format Guide

For CSV files, include a numeric flux column. A time column is optional.

time,flux
0.0,1.0002
0.02,0.9998
0.04,0.9912
0.06,0.9915

Minimum 30 data points required. Kepler 3197-cadence observations fully supported.

Screening Stages

Detection Pipeline

01
Photometry Ingestion

Upload time-series stellar flux from Kepler, TESS, or ground-based surveys.

02
Noise Detrending

Filter instrumental noise, sensor drift, and low-frequency stellar pulsations.

03
BLS Transit Search

Scan trial periods (0.5–20 days) with Box Least Squares to detect recurring transit dips.

04
Feature Extraction

Calculate transit depth, duration, ingress/egress ratios, and signal-to-noise metrics.

05
ML Screening

Evaluate the feature vector through tuned XGBoost, Random Forest, CNN, and SVM models.

06
Candidate Assessment

Calibrated verdict, confidence, diagnostic plots, and downloadable JSON report.

Engine Settings

Astrophysical Parameters

  • Transit Search Method: Box Least Squares (Astropy BLS periodogram)
  • Period Search Grid: 0.5 to 20.0 days (duration grid: 1 to 12 hours)
  • Primary Decision Model: Tuned XGBoost Classifier (composite cross-validation score)
  • Feature Pipeline: 15 astrophysical and statistical indicators (energy, entropy, depth, duration)
  • Candidate Vetting Criteria: Periodic dip + BLS SNR ≥ 3.0 + ML classification confidence

No analysis has been run yet.

Submit a light curve in the Analyze tab to view screening results.

Total Analyses
0
Planet Candidates
0
Candidate Rate
0.0%
Active Decision Model: XGBoost
SourceVerdictConfidenceDecision ModelDateAction

ExoDip is a candidate screening tool designed to help researchers, students, and astronomy enthusiasts analyze stellar light curves for signatures of transiting exoplanets. Using a combination of Box Least Squares (BLS) period searching, astrophysical feature extraction, and an ensemble of machine learning classifiers, ExoDip evaluates raw photometry to identify candidate transit events.

Scientific Notice: ExoDip is a candidate screening tool, not a confirmation pipeline. Exoplanet confirmation requires extensive follow-up observations, including high-resolution imaging, radial velocity spectroscopy, and statistical validation against astrophysical false positives (such as eclipsing binaries and background blended stars).
Core Technologies
Python 3

Modern scientific runtime and high-performance computing environment.

Lightkurve & Astropy

Photometric transit modeling, BLS search, and astronomical time-series tools.

NumPy & Pandas

Array processing, mathematical transformations, and tabular metadata management.

Scikit-learn & XGBoost

Supervised gradient boosting, random forests, and calibrated decision boundaries.

Scientific Architecture

Detection & Screening Pipeline

01
Photometric Ingestion

High-precision stellar flux measurements from space-borne (Kepler, TESS) or ground observatories.

02
Detrending & Calibration

Systematic noise mitigation, baseline normalization, and removal of instrumental artifacts and stellar flares.

03
BLS Periodic Dip Search

Astropy BLS periodogram scans trial orbital periods (0.5–20 days) to detect periodic box-shaped dips.

04
Morphological Profiling

Calculation of 15 key astrophysical features: transit depth, duration, SNR, signal energy, Shannon entropy, and skewness.

05
Machine Learning Ensemble

Supervised consensus combining tuned XGBoost, Random Forest, Support Vector Machines, and Deep Convolutional Networks.

06
Candidate Screening Verdict

Calibrated confidence scores, detection telemetry, diagnostic transit charts, and downloadable JSON reports.

Getting Started with ExoDip

  1. Prepare Photometric Data: Obtain a time series of stellar brightness (Kepler, TESS, or ground-based photometry).
  2. Navigate to Analyze: Use the top navigation bar to select the Analyze page.
  3. Upload or Select: Drop your CSV, TXT, or NPY file into the uploader, or choose a held-out test set row.
  4. Initiate Screening: Click the Analyze Light Curve button.
  5. Inspect Detection Telemetry: Review the detected dips, transit depth, duration, and BLS period.
  6. Export Findings: Download the complete JSON telemetry report using the Download Report button.

Supported Input Formats

  • Standard CSV Format: A comma-separated file with a flux column. A time column is optional.
    time,flux
    0.000,1.0002
    0.020,0.9998
    0.041,0.9912
    0.061,0.9915
  • Kepler Test Set Row (exoTest format): 1 row with 3197 whitespace or comma-separated flux values (FLUX.1 to FLUX.3197).
  • Numpy Array (.npy): 1-D array of float flux values or 2-D array of shape (N, 1).
  • Whitespace-separated TXT: Space-delimited numeric columns containing flux measurements.

How the Pipeline Works

  • Photometric Normalization: Flux values are detrended and smoothed using a uniform box filter to isolate local fluctuations while preserving transit dip profiles.
  • Box Least Squares (BLS): An Astropy BLS periodogram scans trial periods from 0.5 to 20 days with trial transit durations from 1 to 12 hours to search for periodic box-shaped occultations.
  • Feature Extraction: 15 distinct morphological and statistical features are computed, including transit depth, duration, noise standard deviation, skewness, kurtosis, signal energy, and spectral entropy.
  • Ensemble Decision Logic: Calibrated XGBoost and Random Forest models evaluate the feature vector alongside BLS transit significance to assign the final candidate classification.

Understanding Results

  • Period (Days): The best-fit orbital period detected by the Box Least Squares periodogram.
  • Transit Depth (%): The fraction of stellar flux blocked during transit mid-point: δ = ΔF / F ≈ (R_p / R_*)^2
  • BLS SNR: The signal-to-noise ratio of the transit dip relative to residual stellar noise. High SNR values (> 5.0) indicate statistically significant transit shapes.
  • Screening Confidence: The model's calibrated probabilistic assessment that the signal matches bona fide planetary transit profiles rather than stellar variability or noise.

Important Limitations & Astrophysical Caveats

  • False Positives: Eclipsing binary stars (EB), grazing binaries, and background blended stars can mimic planetary transits.
  • Stellar Activity: Starspots, stellar flares, and rotation can introduce spurious periodic dips.
  • Confirmation Required: Candidate status is an initial screening recommendation. Confirmation requires high-precision radial velocity spectroscopy (to measure planetary mass) and high-resolution imaging (to rule out background companions).

Frequently Asked Questions

Q: What is the difference between an exoplanet candidate and a confirmed exoplanet?
A: A candidate exhibits transit-like signals in photometric data that have not yet undergone independent observational confirmation (such as spectroscopic mass determination).

Q: Why is XGBoost used as the primary decision model?
A: On our held-out benchmark evaluation, tuned XGBoost achieved the highest composite score (balanced accuracy, precision-recall, and ROC-AUC) among the ensemble classifiers tested on the Kepler dataset.

Q: What photometric precision is required?
A: ExoDip can detect transit depths as low as ~0.1% (1000 ppm) in clean photometry. Space-based observations (Kepler, TESS) generally meet this requirement; ground-based data may require additional preprocessing to achieve comparable sensitivity.