# StarFYI

> Comprehensive astronomy encyclopedia — stars, constellations, exoplanets, and deep-sky objects. Harvard spectral classification (OBAFGKM), photometric data (apparent/absolute magnitude), physical properties (mass, radius, luminosity, temperature), positional data (RA/Dec), and star comparisons.

## Data Scope
- Stars with photometric properties (apparent/absolute magnitude, color index)
- Physical properties (mass, radius, luminosity in solar units, temperature in Kelvin)
- Positional data (right ascension, declination)
- 88 IAU-recognized constellations with families, areas, and quadrant data
- Harvard spectral classification (O, B, A, F, G, K, M) with temperature ranges
- Exoplanets with discovery methods, orbital parameters, and physical properties
- Deep-sky objects (galaxies, nebulae, star clusters, planetary nebulae, supernova remnants)
- Star comparisons (N² pages) with side-by-side property analysis
- Glossary terms organized by astronomy category
- Guides in series with full markdown content
- 9 interactive tools: magnitude calculator, habitable zone estimator, constellation finder, and more
- 15 languages supported with i18n

## URL Patterns
- Append `.md` to any URL for plain-text markdown format.
- i18n: URL prefix `/{lang}` for non-English (ko, ja, zh-hans, es, fr, de, pt, ru, vi, tr, ar, hi, th, id).
- `/` — Homepage with featured stars and stats (e.g. `/`)
- `/stars/` — Browse all stars (e.g. `/stars/`)
- `/star/{slug}/` — Star detail page (e.g. `/star/sirius/`)
- `/constellations/` — Browse all 88 constellations (e.g. `/constellations/`)
- `/constellation/{slug}/` — Constellation detail (e.g. `/constellation/orion/`)
- `/spectral-classes/` — Harvard spectral classification OBAFGKM (e.g. `/spectral-classes/`)
- `/spectral-class/{slug}/` — Spectral class detail (e.g. `/spectral-class/g/`)
- `/exoplanets/` — Browse exoplanets (e.g. `/exoplanets/`)
- `/exoplanet/{slug}/` — Exoplanet detail (e.g. `/exoplanet/proxima-centauri-b/`)
- `/deep-sky/` — Browse deep-sky objects (e.g. `/deep-sky/`)
- `/deep-sky/{slug}/` — Deep-sky object detail (e.g. `/deep-sky/andromeda-galaxy/`)
- `/compare/` — Star comparison index (e.g. `/compare/`)
- `/compare/{slug1}/vs/{slug2}/` — Star comparison: magnitude, distance, spectral class (e.g. `/compare/betelgeuse/vs/sirius/`)
- `/deep-sky/compare/` — Deep-sky comparison index (galaxies, nebulae, clusters) (e.g. `/deep-sky/compare/`)
- `/deep-sky/compare/{slug1}/vs/{slug2}/` — Deep-sky comparison: magnitude, apparent size, surface brightness (e.g. `/deep-sky/compare/andromeda-galaxy/vs/triangulum-galaxy/`)
- `/glossary/` — Astronomy glossary (e.g. `/glossary/`)
- `/glossary/{slug}/` — Glossary term (e.g. `/glossary/parallax/`)
- `/guide/` — Astronomy guides (e.g. `/guide/`)
- `/guide/{slug}/` — Guide article (e.g. `/guide/stargazing-basics/`)
- `/tools/` — Interactive astronomy tools (e.g. `/tools/`)
- `/tools/{slug}/` — Tool page (e.g. `/tools/star-magnitude-calculator/`)
- `/constellation/{slug}/mythology/` — Constellation mythology (e.g. `/constellation/orion/mythology/`)
- `/search/` — Search stars, constellations, exoplanets (e.g. `/search/?q=sirius`)

## Browse
- [All Stars](https://starfyi.com/stars/)
- [Constellations (88)](https://starfyi.com/constellations/)
- [Spectral Classes (OBAFGKM)](https://starfyi.com/spectral-classes/)
- [Exoplanets](https://starfyi.com/exoplanets/)
- [Deep-Sky Objects](https://starfyi.com/deep-sky/)
- [Star Comparisons](https://starfyi.com/compare/)

## Interactive Tools
- [Star Magnitude Calculator](https://starfyi.com/tools/star-magnitude-calculator/)
- [Habitable Zone Estimator](https://starfyi.com/tools/habitable-zone-estimator/)
- [Constellation Finder](https://starfyi.com/tools/constellation-finder/)
- [Stellar Evolution Tracker](https://starfyi.com/tools/stellar-evolution-tracker/)
- [Light-Year Distance Calculator](https://starfyi.com/tools/light-year-calculator/)
- [Planet Gravity Calculator](https://starfyi.com/tools/planet-gravity-calculator/)
- [Tonight's Sky Guide](https://starfyi.com/tools/tonight-sky-guide/)
- [Star Type Classifier](https://starfyi.com/tools/star-type-classifier/)
- [Exoplanet Explorer](https://starfyi.com/tools/exoplanet-explorer/)

## Learn
- [Astronomy Glossary](https://starfyi.com/glossary/)
- [Guides](https://starfyi.com/guide/)

## Embed Widget
- [StarFYI Widget Docs](https://widget.starfyi.com)
- [starfyi-embed on npm](https://www.npmjs.com/package/starfyi-embed)
- [starfyi-embed on GitHub](https://github.com/fyipedia/starfyi-embed)

## REST API

Free REST API. No authentication required. JSON responses. CORS enabled.

| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/api/v1/stars/` | List stars (DRF, paginated) |
| GET | `/api/v1/stars/{slug}/` | Star detail |
| GET | `/api/v1/constellations/` | Constellations (DRF, paginated) |
| GET | `/api/v1/spectral-classes/` | Spectral classes (DRF, paginated) |
| GET | `/api/v1/exoplanets/` | Exoplanets (DRF, paginated) |
| GET | `/api/v1/deep-sky/` | Deep-sky objects (DRF, paginated) |
| GET | `/api/v1/glossary/` | Glossary terms (DRF, paginated) |
| GET | `/api/v1/guides/` | Guides (DRF, paginated) |
| GET | `/api/v1/tools/` | Interactive tools (DRF, paginated) |
| GET | `/api/v1/faqs/` | FAQs (DRF, paginated) |
| GET | `/api/v1/search/?q={query}` | Unified search (DRF) |
| GET | `/api/v1/stats/` | Site statistics |
| GET | `/api/search/suggest/?q={query}` | Search autocomplete |

```bash
curl -s "https://starfyi.com/api/v1/stars/"
```

[API Docs](https://starfyi.com/developers/) · [OpenAPI Spec](https://starfyi.com/api/openapi.json)

## Developer Tools
- **PyPI**: `pip install starfyi` — [starfyi](https://pypi.org/project/starfyi/) — Star catalog, constellation data, spectral classification
- **Embed Widget**: [starfyi-embed](https://widget.starfyi.com)

## Science FYI Family

Part of [FYIPedia](https://fyipedia.com) developer tools ecosystem.
- [ChemFYI](https://chemfyi.com) — Periodic table, elements, compounds, reactions
- [AlloyFYI](https://alloyfyi.com) — Metal alloys, compositions, properties
- [GemFYI](https://gemfyi.com) — Gemstones, mineralogy, grading, origins
- [MineralFYI](https://mineralfyi.com) — 6,215 minerals, crystal systems, Mohs hardness

## Images (CDN)

OG images for all entities at https://cdn.starfyi.com/og/{type}/{slug}.png
- https://cdn.starfyi.com/og/homepage.png

## Full Index
- [Full content index](https://starfyi.com/llms-full.txt)
- [XML Sitemap](https://starfyi.com/sitemap.xml)