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Privacy policy
Planetarium 3D (sextans.eu) · updated 20 October 2026
You can use the planetarium without an account and without profiling cookies. This page explains what data it processes, why, with which providers and for how long. The Italian version is the reference text.
Data controller
Sergio Baldaro, Via Mirabello 20, Pavia (Italy)
Privacy contact: sebaldar@gmail.com
What data, why and on what legal basis
| Data | Why | Legal basis |
|---|---|---|
| IP address and technical request data (browser, time) | Running the site and protecting it from abuse; a per-IP counter limits the daily questions to the assistant and the sign-in emails | Legitimate interest in the security and operation of the service |
| Observing location (latitude and longitude) | Computing the sky as seen from that place. GPS is used only if you allow it in the browser; otherwise the location is estimated from the device time zone, without sending anything. The location you choose is stored only in your browser. | Performance of the service you request |
| Questions to the assistant | Answering them. The text is sent to the language model provider and is not recorded in our logs (only the amount of text processed and the credits used are recorded). | Performance of the service you request |
| Email (only if you create an account) | Sending you the sign-in link, valid for 15 minutes; managing your assistant credits | Performance of the contract |
| Credit purchases | Payment takes place on Stripe: we receive the outcome and the amount, not your card details | Performance of the contract; tax obligations |
Providers that receive data
| Provider | What it receives | When |
|---|---|---|
| Hetzner Online (Germany), site hosting | All site traffic | Always |
| IONOS AI Hub (IONOS SE, servers in Germany) | The text of your questions to the assistant and the astronomical data needed to answer | When you use the assistant |
| OpenAI (United States) | The guided tour sentences (names of celestial objects, facts, altitude and direction) to generate their voice, from our server, without your IP; never your questions or your location. Sentences and generated audio stay in our server's cache | Only when you listen to the “Tonight's sky” tour with the “Natural voice for the tour” option on (it can be turned off in Advanced) |
| OpenAI (United States) | The text read aloud for the view description and the assistant's answers (which may echo your question or mention a place), to generate its voice, from our server, without your IP. Our server does not store it | Only when you press “Describe the view” or ask the assistant a question by voice, with the “Natural voice for description and assistant” option on (it can be turned off in Advanced) |
| Open-Meteo (Switzerland) | The coordinates of the location, from our server, without your IP | When you ask the assistant about the weather or sky visibility, open “What's up tonight” or watch the sky in real time (coordinates rounded to about 10 km) |
| OpenStreetMap Foundation (United Kingdom) | Your IP and the map area shown, from your browser | Only when you open the map to choose a location |
| CDS, Centre de Données astronomiques de Strasbourg (France) | Your IP and the sky coordinates of the object you zoom in on, from your browser | Only when you zoom in on a galaxy, nebula or cluster with the "Deep-sky photos" option on (it can be turned off in Advanced) |
| Stripe Payments Europe (Ireland) | The payment details you enter on its page | Only when you buy credits |
| Dominiofaidate.it, email service | Your email address and the sign-in link | Only when you ask to sign in |
The site libraries (Three.js, OpenLayers) are served from our server: opening the planetarium does not contact other sites, except CDS for deep-sky photos when you request them by zooming in. The list of places comes from GeoNames (CC BY 4.0 licence) and is looked up on our server, without sending anything to GeoNames.
Telescope
If you connect a telescope (Tools › Telescope), the browser talks directly to the Alpaca bridge or to the telescope on your computer or local network: commands and positions do not go through our server. The bridge address is stored only in your browser.
How long
- Per-IP counters: in memory, reset every day.
- Application logs: rotated, at most 5 files of 10 MB.
- Web server logs (IP address, requested page, time): 6 months.
- Sign-in links: 15 minutes; account session: 30 days.
- Account and credit movements: as long as the account exists; billing data for the period required by law.
Data stored in your browser
The planetarium uses no cookies. It stores in the browser's localStorage, only for you, the
language, display preferences (sky brightness, labels, Earth visible), the chosen location and, if you sign
in, the session token. This is technical data needed for the service: it is not used to track you and you
can delete it from your browser settings.
Equipment, custom horizons and the observing log (sessions, site, date, targets, outcomes and notes) are saved in this browser. You can export and import them using a JSON file; they are not synced with your account. Planning requests in chat send the equipment name and aperture and the applicable horizon to the assistant service, together with the site and date. Observing log notes are not included in those requests.
Custom scenarios (names, descriptions and commands) are also saved locally and can be exported as JSON. Online execution sends simulation commands to the engine; names and descriptions stay in the browser.
Your rights
You can request access to, rectification, erasure, restriction and portability of your data, and object to processing based on legitimate interest, by writing to the contact above. You can also lodge a complaint with the Italian data protection authority, the Garante per la protezione dei dati personali (garanteprivacy.it), or with the authority of your country.
We do no profiling or automated decision-making, and we use no analytics or advertising tools.