Research

Research Roadmap: Twilight (Syafaq) and Crescent Visibility

Key Research Questions:

A. Fundamental Astronomical & Atmospheric Questions

1. How does twilight sky brightness (syafaq) affect the minimum detectable contrast between the crescent Moon and the background sky?
2. What are the dominant atmospheric parameters (aerosols, humidity, air mass) influencing crescent visibility during twilight in tropical regions?
3. How do geometric parameters (elongation, altitude, phase, and lunar age) interact with twilight brightness in determining crescent visibility?
4. To what extent do existing classical and modern visibility models adequately represent twilight conditions in low-latitude (tropical) atmospheres?

B. Observational & Empirical Questions

1. What empirical thresholds of crescent visibility can be derived from systematic observations under varying twilight conditions?
2. How consistent are naked-eye, optical-aided (binocular/CCD), and imaging-based detections of the crescent during twilight?
3. What discrepancies exist between predicted visibility and actual observational outcomes under different twilight intensities?
4. How can citizen science observations be standardized to reliably capture twilight-related visibility data?

C. Computational Modeling & Simulation Questions

1. How can twilight brightness be quantitatively integrated into numerical crescent visibility models?
2. What probabilistic visibility maps (POD maps) best represent the combined effects of geometry and twilight scattering?
3. How accurate are simulation-based predictions compared to long-term observational datasets?
4. Can machine learning models improve crescent detection by accounting for complex twilight-atmospheric interactions?

D. Hisab–Rukyat & Calendar Integration Questions

1. How should twilight-influenced visibility data be incorporated into contemporary hisab–rukyat criteria?
2. What level of uncertainty caused by twilight effects is acceptable for calendar determination?
3. Can harmonized criteria be formulated that remain valid across different atmospheric regimes?
4. How do twilight-based visibility thresholds impact regional versus global Hijri calendar unification efforts?

E. Jurisprudential (Fiqh) & Normative Questions

1. How does empirical twilight-based visibility data reshape classical fiqh interpretations of rukyat hilal?
2. To what extent can scientifically modeled visibility substitute or complement direct visual sighting in Islamic law?
3. How should conflicting observational reports during strong twilight conditions be evaluated legally?
4. What fiqh framework best accommodates probabilistic and data-driven crescent visibility models?

F. Societal, Policy, and Future-Oriented Questions

1. How can public understanding of twilight effects improve trust in crescent visibility decisions?
2. What policy implications arise from adopting twilight-aware visibility criteria at national and international levels?
3. How can technology-driven observation systems reduce subjectivity in twilight crescent reports?
4. What role will AI-assisted detection play in the future standardization of crescent visibility under twilight conditions?