Astronomy is daunting for beginners — there is, after all, a whole universe out there — but the software side of it need not be. This page covers the four categories of program an amateur actually uses, with an honest note attached: nothing here is endorsed, sponsored or supported by this guide. Software changes, projects are abandoned, and links move. Always download from the project's own site rather than a third-party mirror, keep your machine's security software current, and scan anything you are not certain about.
Planetarium and sky-chart programs
The first thing to install. A planetarium program renders the sky from your own coordinates at any date and time, which lets you plan a session indoors, work out what is above the horizon and when, check whether an object clears the treeline, and identify what you saw afterwards.
- Stellarium - free, open source, available for desktop and mobile, and the usual first recommendation. Photorealistic sky rendering, a very large object catalogue, accurate atmospheric and light-pollution simulation, and the ability to set an observer's horizon profile — which is genuinely useful in a valley where terrain hides a large part of the sky.
- KStars - free and open source, with a strong emphasis on integrating planning with actual equipment control. Its companion module handles mount control, guiding, focusing and imaging sequences, which makes it a natural choice for anyone heading toward automated imaging.
Both will show the sky at 49 degrees north correctly, including the circumpolar region and the fact that summer nights here never reach full astronomical darkness. Set your location precisely — a few kilometres matters for horizon profiles in mountain country.
Ephemeris and event tools
For satellite passes, planet positions, conjunctions and the timing of specific events, web tools are usually more convenient than desktop software because they need no updating.
- Heavens-Above - the long-standing reference for satellite predictions, including the International Space Station, calculated for your exact coordinates.
- In-The-Sky.org - night-sky event guides, ephemerides and interactive charts.
- NASA's monthly skywatching summary - a short, reliable overview of what is worth looking at each month.
Telescope and mount control
Beyond the hand controller supplied with a mount there is a substantial ecosystem of third-party control software, much of it free. The important thing to understand is that most of it is built on one of two interface standards, and which one you use largely follows from your operating system.
- ASCOM - the long-established Windows standard. A device driver framework that lets any compliant program talk to any compliant mount, camera, focuser or filter wheel. If you buy hardware and want it to work with software you have not chosen yet, ASCOM compliance is the specification to look for.
- INDI - the equivalent for Linux and macOS, open source, and designed around a client-server model so that the machine at the telescope and the machine you are sitting at need not be the same one. Widely used on small single-board computers mounted on the telescope itself.
A general caution about automation: it solves problems you have, not problems you do not have yet. A beginner with a manual Dobsonian learns the sky far faster than a beginner with a computerised mount, because finding things yourself is how the sky gets learned. Automation earns its place when you start imaging, where unattended multi-hour sequences are the whole point.
Capture, stacking and processing
Astrophotography is a stacking exercise — many short frames averaged together — and that requires software to align, combine and then stretch the result.
- Siril - free and open source, and genuinely capable. Handles calibration with darks, flats and bias frames, registration, stacking, background gradient extraction — which matters a great deal from a light-polluted valley site — colour calibration and stretching. A reasonable place to start before spending money.
Commercial packages exist at every price point and several are excellent, but the free tools will take you a long way and will teach you what the paid ones are actually doing. The astrophotography page covers the capture side, including calibration frames and why flats matter more from a bright site.
What software cannot do
Two closing cautions worth stating plainly.
First, a planetarium program models a perfect sky. It will happily show you an object at eight degrees altitude that is, from the valley floor, entirely buried in horizon glow and atmosphere. Cross-check anything low against what the light pollution and seasonal sky pages say about this latitude before planning a night around it.
Second, no amount of software substitutes for time outside. The observers who see the most are, without exception, the ones who go out most often — including on the marginal nights, with the small instrument, for half an hour. On this coast that is the difference between forty sessions a year and four.