This page provides a complete sample image archive and step-by-step instructions for reviewing Meridian — Deep Sky Catalog.

Meridian is a read-only catalog and visualization tool for deep-sky astrophotography files (FITS/XISF) stored on the user's own Mac. It has no accounts or logins, so there is no demo account; all app content comes from image files the user adds. The archive below contains real telescope data (three deep-sky objects: the galaxies M90, NGC 3718, and Holmberg II) and populates every view of the app.

1. Download the sample archive

Download: meridian-sample-archive.zip (440 MB)

Unzip it (double-click in Finder). You will get a folder named meridian-sample-archive containing three object folders with raw FITS/XISF light frames and a finished JPG image for each object.

2. Add the folder to Meridian

  1. Launch Meridian.
  2. On the welcome screen, click Add Folder and select the unzipped meridian-sample-archive folder. (If the app is past the welcome screen, use Source Files → Add Watched Folder in the toolbar.)
  3. Meridian scans the folder, identifies the objects, and generates thumbnails. This takes under a minute.

3. What each view shows

  • Catalog — the three imaged objects with hero images, imaging sessions, equipment, and integration time.
  • Source Files — the actual files on disk; select any FITS/XISF file to see its full header metadata and an auto-stretched preview.
  • Equipment — the telescope and camera profiles read automatically from the file headers.
  • My Sky — an interactive sky map (loads sky-survey imagery over the network) with the imaged objects marked at their real coordinates.
  • Wish List — future imaging targets. Click + and add any object (for example, M51) to see it with rise/set and altitude planning.
  • Statistics — archive analytics (integration by object, filters, monthly activity). Optionally run Star Analysis from the Statistics sidebar to compute star-quality metrics from the sample frames.

4. Optional: observer location

For visibility planning (rise/set times and altitude charts in Wish List), open Settings → Location and either allow location access or type any coordinates (for example, latitude 37.33, longitude -122.01).

Notes

  • No account, login, API key, or third-party software is required to review any part of the app.
  • Meridian never modifies, moves, or renames the image files it catalogs; the archive is read-only to the app.
  • Cloud plate solving and the optional local ASTAP integration are off by default and are not needed for review.