Credits and licences
Star Trail Stacker uses photographs, data, map sources, fonts and software made by other people. This page names each one with its author or owner, its source, the licence it is used under and where on the site it appears. Night photographs not listed here are the site owner’s own, as the about page says.
Photographs and telescope images
Pictures shown on the site that someone else made. Where a picture was resized or recompressed, the row says so; every adaptation of a CC BY-SA picture is offered under the same licence as the original.
| Work | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| M51 and its companion, heic0506a (resized, recompressed) | NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA) | ESA/Hubble image | CC BY 4.0 | Home, Deep-sky guide |
| M51: one exposure / 24-frame luminance integration (bias calibrated, registered, stacked, cropped and resized) | Peter Sloan · University of Bath | Whirlpool Galaxy dataset, BATH-01225 | CC BY 4.0 | Features, Gallery, app mode and setting examples |
| Moon: frame selection and wavelet sharpening examples, adapted (video excerpt, registered, stacked, cropped, resized and recompressed) | Justin Dolske | Moon video on Wikimedia Commons | CC BY-SA 2.0; these derivatives use the same licence | Planetary setting examples |
| Cassini Jupiter portrait, PIA04866 (resized, recompressed) | NASA/JPL/Space Science Institute | NASA Photojournal | NASA media usage guidelines | Home, Features, Planetary guide; no endorsement implied |
| MobilTelesco, run 10marrun1: 50 realme 12+ frames, stacked here (200% crops) | Shantanusinh Parmar | Zenodo record 15846941 | CC BY 4.0 | Home |
| “CCD Dark Frame”, adapted (recompressed) | H. Raab (User:Vesta), Johannes-Kepler-Observatory, Linz | Wikimedia Commons | CC BY-SA 3.0, one of the file’s licensing options | Calibration frames |
| “Dark frame subtraction”, adapted (resized, recompressed) | Spigget | Wikimedia Commons | CC BY-SA 4.0 | Calibration frames |
| “Dark Frame”, adapted (recompressed) | Rawastrodata | Wikimedia Commons | CC BY-SA 3.0, one of the file’s licensing options | Calibration frames |
| “Sunflower field Milky Way”, adapted (resized, recompressed) | Juliancolton | Wikimedia Commons | CC BY-SA 4.0 | Calibration frames |
| “Comet NEOWISE (50155614036)” | Deborah Lee Soltesz | Wikimedia Commons | CC0 1.0 | The Comet card on the home page |
| All-sky frames, “Planes and meteors”, 13 May 2021, cropped | Yebes Observatory (image property of Yebes Observatory) | Yebes Observatory All Sky Gallery | Public use with credit | Removing trails before stacking, Satellites in star trails, What makes it different, Measured beside a desktop app, What it can read |
| NGC 2392, EFOSC2 frames from the ESO 3.6 m telescope at La Silla | European Southern Observatory. Based on observations collected at the European Southern Observatory under ESO programme 60.A-9501(B). | ESO Science Archive | CC BY 4.0 | Bring out faint structure, Does drizzle help your night, the Planetary card on the home page, What it can read |
| “A set of allsky camera images from latitude 55 degrees North” (Zenodo record 3736793) | Peter Thejll | Zenodo | CC BY 4.0 | The plain and equalised comparison on the home page and How it works, also used as the preview image of several pages; the measurements on About and Measured beside a desktop app |
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Data
Data the site ships or your browser reads while a page is open.
| Data | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| Light Pollution Atlas, 2025, built from NOAA/NASA VIIRS night-lights data via the Earth Observation Group | David Lorenz | Light Pollution Atlas | Used with the author’s written permission; no public licence | Light pollution map; ground darkness on Northern lights tonight and Aurora forecast |
| Aurora grid (OVATION), Kp, solar wind, hemispheric power, forecasts, scales and alerts | NOAA Space Weather Prediction Center | swpc.noaa.gov | Public domain | Northern lights tonight and its regional pages, Aurora forecast, Kp index, Geomagnetic storm |
| Locationforecast (cloud and temperature) | MET Norway | api.met.no | CC BY 4.0 | Northern lights tonight and its regional pages, Aurora forecast |
| World Magnetic Model WMM2025 coefficients | NOAA National Centers for Environmental Information | NOAA NCEI | Public domain (U.S. Government work) | The compass correction in Sky Director |
| Lensfun lens database: 1,520 lenses and 6,430 distortion calibrations, reformatted as lens-db.json | The Lensfun project and its contributors | lensfun.github.io | CC BY-SA 3.0; our derived file is offered under the same licence (notice) | Lens matching in the stacker; What your lens does; the distortion figure on Coma and astigmatism |
Maps
The base map is one archive served from this domain, so drawing it sends no request to another site.
| Map data | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| Base map: the Protomaps planet build of 7 September 2026, cut to zoom 13 and hosted here | © OpenStreetMap contributors; tiles built by Protomaps | OpenStreetMap | Open Database Licence (ODbL) 1.0 | Light pollution map, the map on Aurora forecast |
| Natural Earth: in the base map, and the 1:110m coastline drawn on the aurora disc | Natural Earth | naturalearthdata.com | Public domain | Light pollution map, Aurora forecast, Northern lights tonight |
| Time-zone boundaries, packed into the tz-lookup table listed under Software | timezone-boundary-builder, from © OpenStreetMap contributors data | timezone-boundary-builder | Open Database Licence (ODbL) 1.0 | Local times on the Light pollution map and the aurora pages (full notice) |
Measurement and test data
Files the tool was measured or tested on. The pages listed quote results measured on them.
| Data | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| All-sky frames from the same camera on other nights (Zenodo record 3754088) | Peter Thejll | Zenodo | CC BY 4.0 | About, How it works |
| “Dataset for: ASTA (Automated Satellite Tracking for Astronomy)”, MeerLICHT frames (Zenodo record 11642424) | Fiorenzo Stoppa | Zenodo | CC BY 4.0 | The trail-search results on the home page |
| “MobilTelesco: A Smartphone based Astrophotography Dataset” (2025) | Shantanusinh Parmar | Zenodo | CC BY 4.0 | What it can read |
| HDR+ Burst Photography Dataset (SIGGRAPH Asia 2016) | Samuel W. Hasinoff and colleagues at Google | hdrplusdata.org | CC BY-SA 4.0 | What it can read |
Streak detection training set (release training): 512 px tiles with
hand-labelled trails |
gkyle | github.com/gkyle/startrails | MIT | What it can read |
| “2011-08-27 22-34-12 iridium flare” (Nikon D300) | Thomas Bresson | Wikimedia Commons | CC BY 3.0 | What it can read |
| “Milky Way taken from Ballykelly” (Canon EOS 5D Mark II) | john.purvis | Wikimedia Commons | CC BY 2.0 | What it can read |
| “Helicopter Streaks Across Sky” (Samsung NX1000) | Sam Mellors | Wikimedia Commons | CC BY 3.0 | What it can read |
| Camera RAW sample files (CR2, CR3, NEF, RAF, ORF, RW2, PEF) | The contributors of raw.pixls.us | raw.pixls.us | CC0 1.0 | What it can read |
| Lunar SER sample captures | PlanetarySystemStacker (Rolf Hempel) | PlanetarySystemStacker | GPL-3.0 | What it can read |
| A guided Pentax 645Z night of PEF files | Wei-Hao Wang | Not published | Used with his permission | What it can read, About, Star trails on a Mac |
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Fonts
Both fonts are served from this domain; no font is loaded from another site.
| Font | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| Archivo | The Archivo Project Authors | github.com/Omnibus-Type/Archivo | SIL Open Font License 1.1 | Every page |
| IBM Plex Mono | IBM Corp., with Reserved Font Name “Plex” | github.com/IBM/plex | SIL Open Font License 1.1 | Every page |
Software
Third-party code shipped with the site. Every file is served from this domain. Where we changed a library, the linked notice says exactly what changed.
| Library | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| Leaflet 1.9.4, with one documented change | Volodymyr Agafonkin; CloudMade | leafletjs.com | BSD 2-Clause | Light pollution map, the map on Aurora forecast |
| protomaps-leaflet 5.1.0, with two documented changes | Protomaps LLC | protomaps.com | BSD 3-Clause | Light pollution map, the map on Aurora forecast |
| @photostructure/tz-lookup 11.6.1, with one line added | PhotoStructure, Inc. | github.com/photostructure/tz-lookup | CC0 1.0 | Local times on the Light pollution map and the aurora pages |
| onnxruntime-web 1.27.0 | Microsoft Corporation | npm: onnxruntime-web | MIT | Served with the stacker for the learned trail check; that check is withdrawn for now, so the runtime is not loaded |
| LibRaw 0.22.2, compiled to WebAssembly | LibRaw LLC; includes code by Dave Coffin (dcraw), Jacek Gozdz (DCB, FBDD), Roland Karlsson (X3F) and Adobe (DNG SDK), listed in its copyright notice | The exact source compiled (how it was built) | CDDL-1.0, one of the two licences LibRaw offers | The stacker, when a RAW file is opened (details) |
| zlib 1.3.2, inside the same WebAssembly module | Jean-loup Gailly and Mark Adler | zlib.net | zlib licence | The stacker, when a RAW file is opened |
| libjpeg 9f, inside the same WebAssembly module | Independent JPEG Group. This software is based in part on the work of the Independent JPEG Group. | ijg.org | IJG licence | The stacker, when a RAW file is opened |
| QR Code Generator for JavaScript 2.0.4 | Kazuhiko Arase | GitHub | MIT | Sky Director |
Moon position: a reduced JavaScript adaptation of ERFA moon98.c |
NumFOCUS Foundation (ERFA), derived from the International Astronomical Union’s SOFA library | github.com/liberfa/erfa | BSD 3-Clause (ERFA licence) | Sky Director |
Code written here from other people’s designs
The frame-registration engine contains no line of another project’s source, but its method follows the work below, whose notices travel with it. The full notice says what was taken from each, what was changed and what was deliberately not read.
| Design | Author or owner | Source | Licence | Used on |
|---|---|---|---|---|
| Triangle-invariant asterism matching (astroalign) | Martin Beroiz | github.com/quatrope/astroalign | MIT | Frame registration in the stacker |
| The RANSAC routine inside astroalign | Andrew D. Straw | By way of astroalign | BSD 3-Clause | Frame registration in the stacker |
Closed-form similarity fit (_umeyama) |
The scikit-image team | scikit-image.org | BSD 3-Clause | Frame registration in the stacker |
If a credit is wrong
If you made something listed here and the credit is wrong or incomplete, or something of yours is on the site and missing from this page, the contact page has the address. It will be corrected.