Your data and Astronomical

For the purposes of UK data protection law (the UK GDPR and the Data Protection Act 2018), I am the controller of the small amount of personal data described on this page.

The way to reach me about privacy, or anything else, is email: hello@thetelescopeman.com. I do not publish a postal address.

You don't sign up for anything. There's no analytics, no crash reporting, no advertising and no update checks in the app, and I don't run a server that receives anything from it. Android's cloud backup is switched off for the app. Some phones' transfer tools can still copy its data when you move to a new phone.

The app asks for your location only when you tap its button, so it knows where the sky is for you: what's up, and where to point. It never tracks you in the background. You can choose approximate location, or type your coordinates in by hand. Your location is kept in the app's own storage on your phone. It only leaves the phone for things you ask for:

• a weather forecast sends your position, rounded to about 11 km (a tenth of a degree), to Open-Meteo (api.open-meteo.com), never your exact position;
• connecting a mount sends your coordinates to your own mount, which needs them to point;
• a polar-alignment export always includes them, and a night-plan export includes them only if you tick the box.

Everything you capture is saved in the app's own storage, and the app uploads nothing. On Android 10 or later it also makes copies other apps can see:

• when you save a stack, a copy of the stacked image and any calibration masters goes in your phone's Download/Astronomical folder. This is on unless you turn it off in Saved images, under Files on your phone;
• when you finish a science stack, the original picture and the adjusted and labelled versions go in Pictures/Astronomical;
• movies you export go in Movies/Astronomical.

Your gallery, and any photo backup you use, can see those folders. Uninstalling the app doesn't remove those copies. Pictures only leave your phone when you, or your own backup, send them.

The app only opens your phone's own camera when you choose a phone-camera feature, such as the phone finder, the exposure test or a phone timelapse, and only while the app is open or its camera notice is showing. The frames stay on your phone. Stop the camera engine to release the camera.

When you start a ZWO, ToupTek or USB video camera, Android also asks for the camera permission. The app needs it to run those cameras, but your phone's own lens isn't opened for them.

The app talks to your own equipment:

• cameras, focusers, filter wheels, rotators and mounts over USB;
• OnStep mounts over Bluetooth, from your phone's list of paired devices;
• mounts, cameras and accessories on your Wi-Fi, at the address you type in.

Equipment links over Wi-Fi aren't encrypted (the astronomy protocols don't support it), so keep them on your own network. A developer tool can scan for Bluetooth devices for twelve seconds and read the list of services on the one you pick, but it never sends them any commands. Bluetooth is only used to find your gear, never to work out where you are. (On Android 11 and older, Android requires the location permission before any Bluetooth scan, so the app has to ask for it.)

The atlas pictures and the optional survey images come from the CDS in Strasbourg (alasky.cds.unistra.fr), which serves the Digitized Sky Survey (DSS2) made by the Space Telescope Science Institute.

• When you open the atlas, it loads the pictures for the part of the sky you're looking at, unless you've switched on Offline only. Atlas pictures are kept on your phone, up to the size limit you choose.
• The CDS sees which patch of sky you asked for and your phone's internet address, as any website does.
• For a survey image, your phone also sends the same browser identification it sends to any website, which usually includes its model and Android version.
• The reference photographs on the object pages (from Wikimedia Commons, ESA/Hubble, ESO and the Digitized Sky Survey) are built into the app and never downloaded. Tapping a credit opens that site in your browser.

Both only happen when you ask:

• A forecast goes to Open-Meteo, and the request also carries your phone's browser identification, which usually includes its model and Android version.
• If you set up plate solving, the app downloads the star database you choose (from under 1 MB to 860 MB) from SourceForge (downloads.sourceforge.net) and its download mirrors, once. That request carries your phone's model and Android version too.
• The quick star-pattern solver uses a small star database built into the app, so it needs no download.

Narration reads an object's catalogue details aloud: in the full app it is off unless you turn it on in Explore, and in Astronomical Lite the narrated tour reads each target aloud unless you untick Read out each target in its plan. It speaks using your phone's own text-to-speech engine. The app hands the words to that engine on your phone and sends nothing itself. If you've set your phone's speech engine to use online voices, that engine's own privacy terms apply.

In Astronomical Lite you can tap the microphone button and say a command, such as “GoTo Messier 45”. The app asks for the microphone permission the first time you tap it. It listens only after you tap the button, until you stop speaking, and at no other time.

Your phone's own speech recogniser turns what you say into words on the device, so the sound never leaves your phone. It needs Android 12 or later with Google's speech services and the offline English (UK) pack; if the pack is missing, the app can ask Android to fetch it. On a phone without an on-device recogniser, voice commands are off and you can type the command instead. The app never uses an online speech service.

The app never records, keeps or sends any audio. It receives only the words, works out the command on your phone, and notes the words in its session log. That log is kept only while the app is open, and it goes into a diagnostics report only if you export one.

The Last night card in your Library sums up your most recent session from what the app already keeps on your phone: your saved images and their looks, the camera engine's health log, the sky-tour journal, how the last session ended and your live mosaic plan. To do that it also keeps a short log of STOP commands and Return to Home results (the newest 200). These logs stay in the app's own storage, are never sent anywhere, and go when you clear the app's storage or uninstall it.

If something goes wrong, you can export a diagnostics report. The app saves it wherever you choose and sends nothing: it's up to you whether you send it to me. Have a read before you do, and leave out anything you'd rather keep to yourself.

It contains:

• your phone's make, model and Android version, the app version and memory figures;
• the USB devices plugged in;
• how many Bluetooth devices it could see, but not which ones;
• your camera's name and settings, and the target you were on;
• the session log, which includes the words of any voice commands, and what your phone's camera can do.

It never contains your coordinates, or the names or addresses of any Bluetooth devices.

• Location (approximate or precise): only when you ask for your position, as above.
• Camera: phone-camera features, and starting ZWO, ToupTek or USB video cameras.
• Microphone: voice commands in Astronomical Lite, only while you speak a command after tapping the microphone button.
• Nearby devices (Bluetooth): OnStep mounts you have paired, and the developer scan.
• Notifications: the running-camera notice and its stop button. Declining them doesn't stop capture.
• Internet: the forecast, atlas and survey pictures, star-database downloads, and gear on your network.
• Keep awake: the camera service keeps the processor awake during capture, and the observing screen stays on while the app is open.

You can withdraw any permission in Android Settings.

Everything the app holds is on your phone. Clearing the app's storage in Android settings, or uninstalling it, removes it all, except the copies in your Download, Pictures and Movies folders and any files you exported yourself, which you delete like any other file. I don't hold any of your data, so there's nothing for me to delete.

The app's own code is free software under the GNU GPL, and so is the camera engine it's built on, so anyone can read what the app does with your data. The camera makers' drivers (ZWO, Player One, ToupTek and SVBONY) are their own closed code, included under their licences.

Under UK data protection law you have the right to:

• ask for a copy of personal data I hold about you;
• have it corrected if it is wrong, or deleted;
• ask me to restrict or stop using it, and object to how I use it;
• receive it in a portable form where that applies.

The app sends me nothing, so in practice the only personal data I could hold that can be linked to you is an email you sent me. To use any of these rights, email hello@thetelescopeman.com. I will reply within one month.

The UK regulator for data protection is the Information Commissioner's Office (ICO). You can complain to the ICO at ico.org.uk/make-a-complaint or by phone on 0303 123 1113.