04. Star Atlas - gordtulloch/Galileo GitHub Wiki

04. Star Atlas

Overview. Every control on this screen has detailed built-in help: hover it, press F1, or click the ? beside the title. See Built-in Help.

The Star Atlas is Galileo's live planetarium. It shows stars, deep-sky objects (Messier, Caldwell, NGC) and solar-system objects for your Observatory's location and the current time, and it is the primary way to pick an imaging target for the night.

Contents

Opening Star Atlas

Click Star Atlas in the left sidebar. The view opens on the sky above your Observatory's latitude and longitude for the current local time. If no Observatory is configured the sky defaults to equatorial coordinates centred on RA 0 h, Dec 0°.

You do not need any hardware connected to use Star Atlas. It works entirely from your Observatory's location data.

Navigating the sky

Action How
Pan Click and drag anywhere on the sky
Zoom in / out Scroll wheel, or the + / – toolbar buttons
Jump to a part of the sky Use the search box or the coordinate entry in the toolbar
Animate (fast-forward time) Not yet implemented

The view always shows the sky as it looks right now from your Observatory. Altitude and azimuth coordinates update live.

Finding an object

Type a name into the Search box in the toolbar — for example M31, NGC 224, Andromeda, or Orion Nebula — and press Enter. The atlas pans and zooms to centre the object. Catalogue IDs, common names and constellation names all work.

Objects shown:

Symbol Meaning
Small dots Stars, sized by magnitude
Open circle Galaxy
Filled circle Open cluster
Filled square Globular cluster
Rectangle Diffuse or emission nebula
Diamond Planetary nebula

Hovering over an object shows its name, type, magnitude, RA/Dec, current altitude and azimuth in a tooltip.

Solar-system objects

The Sun, Moon and the major planets are drawn at their current positions. The Sun and Moon are oversized for visibility at wide field of view. Their positions update with the system clock every few seconds.

Selecting a target

Click on any object (or on a search result) and choose Select from the pop-up. The selected object becomes the Pier's current object:

  • The top bar shows "Current object: M 31" on every screen.
  • Frames captured on the Imaging screen are named after it.
  • The Solve screen's Slew to Target action uses it.
  • Planning > What's Up Tonight shows it as a pinned entry at the top of its list.

The current object is per-Pier and resets when Galileo exits. To clear it, right-click the top bar's current-object label and choose Clear.

Slewing the mount from Star Atlas

If a mount is connected to the selected Pier, clicking on an object shows a Slew To button in the pop-up in addition to Select. Choosing it slews the mount directly to that object without leaving the Star Atlas.

Parked mount: if the mount is parked, Galileo will tell you to unpark it first — the slew is not attempted.

The reticle (see below) tracks the slew's progress.

Mount pointing reticle

When a mount is connected, the Star Atlas draws a reticle (crosshair + circle) at the mount's current pointing position, updated every few seconds while the mount is tracking and every second while it is slewing. This makes it easy to see where the mount is actually pointed versus where you want it.

Horizon overlay

If you have uploaded a horizon file under Options > Star Atlas, the atlas shades the sky below your local horizon in a darker colour. Objects that are obstructed (below the horizon file) are flagged in their tooltips and cannot be slewed to from here.

See Options > Star Atlas for how to upload a horizon file.

Options

Open Options (gear icon in the sidebar, or the cog in the top bar) and choose Star Atlas to configure:

Setting Meaning
Horizon file Upload a .hrz or plain-text altitude–azimuth profile. Saves per Observatory.
Magnitude limit Faintest star shown. Higher numbers show more stars; lower values speed up rendering at wide FOV.
Display DSO labels Show/hide object name labels on the atlas.
Telescope FOV overlay When enabled, draws the field of view of the selected optical tube over the target area.