---
title: "Overlays & Catalogs"
description: "Two side panels turn the sky canvas into a planning instrument: **Sky Overlays** (green tab) draws reference lines, your horizon, and your project fleet on the sky; **Sky Catalogs** (purple tab) controls twelve deep-sky object catalogs. ### Project Overlays Every…"
url: "https://astro-pm.com/docs/sky-view-overlays-catalogs/"
updated: "2026-07-12"
category: Astro PM App Guide / Framing
---

# Overlays & Catalogs

Two side panels turn the sky canvas into a planning instrument: **Sky Overlays** (green tab) draws reference lines, your horizon, and your project fleet on the sky; **Sky Catalogs** (purple tab) controls twelve deep-sky object catalogs.

### Project Overlays

Every project can appear on the sky as its FOV rectangle, color-coded by status – each status individually toggleable: **Planning** (gray), **Active** (blue), **Draft**, **Favorites** (gold), **Unfinished** (orange), **Completed** (green). Click any rectangle for a popup with the project name, coordinates, thumbnail, and a **Go to Project** button. This is your fleet’s sky map: see at a glance where this season’s work is concentrated and what sky you have not touched.

![](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-122019.png)
Past Projects as well as curent view and comparison view showing

### Coordinate Overlays

- **Equatorial Grid** – RA/Dec gridlines.
- **Alt/Az Grid** – altitude/azimuth lines that stay level with your site’s horizon.
- **Ecliptic** – the solar path (also where planets and zodiacal light live).
- **Galactic Plane** – the Milky Way equator, useful when hunting low-extinction sky.

### Observer Overlays

- **Horizon** – the flat 0° altitude line.
- **Custom Horizon (.hrz)** – the site’s real obstruction profile from Equipment → Observatory, drawn in orange. See [Custom Horizons](/docs/custom-horizons/).
- **Horizon panorama** – beyond the line, you can load a 360° panorama image of your actual horizon (2048×1024 PNG with transparent sky). Three sliders align it: **BG Rotate** (0-360° azimuth), **BG Shift** (±20° vertical), and **BG Darkness** (0-0.9). Your real trees, on the real sky.
- **Meridian Line** and **Zenith Marker** (both on by default) – see at a glance when a target transits (and when a flip would happen).
- **Heatmap** – shades the sky green-to-red by observability, with an **Altitude** threshold slider (0-60°, default 30°). A fast visual answer to “where is the good sky right now?”

![](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-122147.png)
Insert your own backyard with phone 360 image easily

### Solar System Overlays

- **Sun Position** and **Moon Position** markers (moon on by default, with phase).
- **Planet Positions** – Mercury through Saturn, labeled.
- **Daylight Sky** – tints the sky blue in daytime, fading through twilight to dark. Scrub the timeline with this on and you can *see* when the sky gets dark enough to image.

### The Twelve Catalogs

   ![](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-122358.png)

Each catalog row has a checkbox, a color/shape swatch, and a **density slider** (0-100%) that filters how many of its objects draw – keeping dense catalogs readable at wide zooms:

| Catalog | Contents | Default density |
| --- | --- | --- |
| Popular Objects | ~200 hand-curated showpieces | 100% |
| Messier | the 110 Messier objects | 100% |
| NGC | 7,840 galaxies, nebulae, clusters | 45% |
| IC | 5,386 fainter objects | 40% |
| Caldwell | 109 bright favorites | 70% |
| Sharpless | 312 H-II emission regions | 70% |
| Barnard | 348 dark nebulae | 25% |
| LBN | 1,445 bright nebulae | 55% |
| LDN | 1,602 dark nebulae | 55% |
| Supernova Remnants | 294 SNRs | 60% |
| Planetary Nebula | 3,000+ PNe | 70% |
| Mandel-Wilson | the “unexplored nebulae” collection | 100% |

All catalogs are embedded – no internet needed. Clicking any object selects it and opens the target HUD with Web / Astrobin / SIMBAD research buttons.

### Names & Angular-Size Circles

**Show Names** labels objects (M31, NGC 7000…). **Angular-Size Circles** draws each object as a circle scaled to its true size on the sky – so you instantly see whether a nebula fills your FOV rectangle or drowns in it. A companion slider (**FOV ≤ 1-25°**, default 5°) hides the circles when zoomed out too far for sizes to be meaningful.

   **Tip:** Framing workflow in one sentence: turn on the catalog your target lives in, enable angular-size circles, pick the NSNS survey matching your filters, and drag the FOV rectangle until the composition sings.