The Sky Surveys panel (blue tab on the right edge) controls what the sky itself looks like: which imagery is behind your framing, and – on the built-in starfield – exactly how stars are drawn, down to the magnitude limit.
The Seven Surveys #
| Survey | What it is |
|---|---|
| Default Survey | Astro PM’s offline starfield: 118,000 Hipparcos/Tycho-2 stars plus a computed Milky Way. Instant, works with no internet, fully adjustable star rendering. |
| DSS2 Color | The Digitized Sky Survey II, red + blue plates combined – real photographic sky, all-sky coverage. |
| DSS2 Red | Red plate only – emission regions stand out. |
| DSS2 Blue | Blue plate only – reflection nebulae and hot stars. |
| NSNS H-alpha | Northern Sky Narrowband Survey, H-alpha channel – preview what your Ha filter will see. |
| NSNS [OIII] | The [OIII] channel of the same survey. |
| NSNS [SII] | The [SII] channel. |
The narrowband surveys are the planning gem: frame an emission target while looking at its actual narrowband structure, not a broadband approximation.
Tile Adjustments (Imagery Surveys) #
When a DSS2 or NSNS survey is active, three sliders tune the imagery:
| Slider | Range | Default |
|---|---|---|
| Brightness | 0.5x – 7.0x | 1.0x |
| Contrast | 0.5x – 3.0x | 1.0x |
| Saturation | 0.0x – 3.0x | 1.0x |
Narrowband tiles are naturally dim – push brightness and saturation to make faint nebulosity readable. Reset All returns the trio to defaults. Settings persist per user.
Star Rendering (Default Survey) #
On the built-in starfield, six controls shape the stars:
| Control | Range | Default | Effect |
|---|---|---|---|
| Star Glow | 0.3x – 8.0x | 1.0x | halo/bloom around stars |
| Star Size | 1.0x – 8.0x | 1.3x | rendered dot radius |
| Mag Limit | 3.0 – 17.0 | 6.0 | faintest star drawn |
| Star Names | Off – mag 11 | Off | classical names (Sirius, Vega…) |
| HIP Names | Off – mag 11 | mag 1.0 | Hipparcos IDs (HIP 12345) |
| Milky Way | brightness 0 – 3.0x | 0.4x | computed nebulosity, checkbox + slider |
Constellation Lines (on by default) draws the classic figures with name labels. Each slider has its own reset button, and a live star-count readout shows how many stars your current magnitude limit puts on screen.
Going Deeper: Gaia DR3 Import #
Out of the box the starfield reaches Hipparcos depth. If you have ASTAP installed with its D50 star database, click Import Gaia DR3: Astro PM converts the ASTAP database into its own format (10-30 seconds, progress shown) and the starfield deepens to roughly magnitude 15 – enough to recognize the star patterns from your actual subs when framing. The Star Database status block shows what is loaded: named stars, HIP count, Gaia status, stars visible at the current limit, and the database total.