Guided tours

• Find the North Star The Plough, the pointers, and your own latitude.
• Arc to Arcturus Follow the handle round to Arcturus and on to Spica.

A tour hands control back between steps, and you can start either of them again from here as often as you like.

The instruments

• This bar Search, layers, framing, sky conditions, night mode and this guide. One opens at a time, and each one names itself when you hover or tab onto it.
• Layers Fifteen switches for what is drawn: names, figures, IAU boundaries, the grids and the ecliptic. Your choices are remembered.
• Sky conditions How dark your sky is, on Bortle's scale, plus the air, the ground, the Milky Way and twinkling. The reading tells you how faint a star you could actually see.
• Framing F Draws your camera's field on the sky: pick a sensor and a focal length and it says whether the target fits.
• Compass Bottom right. It is a control, not a picture — click any point in the dial to look there, or tab to it and steer with the arrow keys. Home faces north; Enter looks straight up.
• Time The bar along the bottom. Drag the track to scrub through the night against the twilight bands, press play to run it, pick another date from the calendar, and NOW returns to the present.
• Location In the pointing readout, top left. Everything horizon-shaped — the ground, the compass, twilight, every rise time — is computed from it, so it is worth correcting.

Gestures

• Drag Swing the view across the sky. Let go mid-drag and it glides.
• Scroll · Pinch Zoom the field of view in and out around the pointer.
• Click a star Opens its card: spectral class, distance, how bright it really is.
• Click a symbol Same for a deep-sky object — the glyphs below are all clickable.
• Click empty sky Washes the constellation whose territory you clicked. Click it again to clear.

Keyboard

• ← ↑ ↓ → Pan by a fraction of the current field, so the step feels equal at any zoom. During a tour they step through it instead.
• + − Zoom in and out from the centre.
• ⌘ +K Search stars, constellations, planets and Messier numbers.
• F Open and close the framing tool.
• ? Open and close this guide.
• Esc Close whatever is open, then drop the current selection.

Deep-sky symbols

The same shapes a printed star atlas uses. Size follows the object's real angular extent; faint objects get a quieter glyph.

• Galaxy
• Open cluster
• Globular cluster
• Planetary nebula
• Bright nebula
• Supernova remnant
• Dark nebula

Label colours

• Vega Amber, monospaced — a named star.
• M 31 Warmer amber, two lines — a deep-sky object and its catalogue number.
• ORION Blue, wide-tracked caps — a constellation figure, the joined-up pattern.
• ORIONIS Slate, widest tracking — the IAU boundary that owns that patch of sky.
• The Plough Italic amber — an informal asterism, not one of the official 88.