Astronomy software Meridian launches in BETA

Meridian is a new native macOS app from Andrew Burwell, that scans your FITS and XISF archive and organizes it into a searchable, visual catalog of your imaging history.

After more than ten years of deep sky imaging, the app's creator found that his archive spanned many drives and folder schemes, with naming conventions that evolved and sometimes contradicted one another. He often forgot what targets had been captured with which setups, whether integration time on a project was complete, or which filters still needed attention. Meridian was built to solve that practical problem. Point the app at your folders and it reads every FITS and XISF header, resolves object names, and rebuilds your work as an organized catalog by target. It never modifies, moves, or renames your files.

What Meridian software does

Meridian performs object resolution across twenty catalogs that together cover more than forty one thousand objects, including Messier, NGC, IC, Caldwell, Sharpless, Barnard, and Abell. Whether your header calls a target NGC 224, M31, or Andromeda Galaxy, Meridian knows it is the same object and merges your data accordingly. It handles spacing differences, varied prefixes, and cross catalog aliases. The full reference database is included with the app, so identification runs locally without requiring an internet connection.

A catalog you can actually use

The Catalog View becomes the heart of your archive. Every target you have imaged appears with your best processed image as the lead, or an auto stretched FITS preview if you have not processed it yet. You will see integration totals, per filter breakdowns, session history across years, and the equipment setups used for each session. You can sort by total hours, constellation, object type, or last imaged date. You can filter by equipment to quickly answer what you have shot with a given telescope or camera. Because all of this is generated from your headers, the view stays accurate as your archive evolves.

Planning and exploration

Meridian includes an interactive sky map that plots your imaging history using Aladin Lite, so you can see at a glance which parts of the sky you have covered across all supported catalogs. A Wish List helps you plan what to capture next. Enter a target and Meridian computes visibility for your observing location, including best months, peak altitude, hours above thirty degrees, transit time, and rise and set. A twenty four hour altitude chart shows exactly when a target peaks. The app can also compare field of view fit across your saved equipment profiles. All of the visibility math runs locally using spherical trigonometry, with no dependence on external ephemeris services.

Insight into your data

A Statistics Dashboard summarizes your work with grand totals, an imaging timeline, filter and sky coverage breakdowns, seeing quality, equipment usage, most revisited targets, and overall archive health. Meridian auto stretches linear FITS and XISF data using a midtone transfer function to create consistent thumbnails, so every light frame becomes immediately visible. A Quick Look extension for Finder lets you press Space on any FITS or XISF file to see an auto stretched preview with header metadata, even when the app is not running.

Who Meridian is for

Meridian is built for Mac based astrophotographers who capture on the Mac or on Windows using tools such as NINA, Sequence Generator Pro, Voyager, or APT, and who process on macOS. If you have accumulated years of FITS and XISF data and want a clear picture of what you have, what is missing, and what to shoot next, Meridian is intended for you. The app runs on Apple Silicon Macs with M1 or later and requires macOS 14 Sonoma or newer.

Availability and pricing

Meridian is available in beta through TestFlight at https://testflight.apple.com/join/6xgTwTtV. The free tier includes archive scanning, the full Catalog View, object resolution across all supported catalogs, auto stretched thumbnails, Quick Look, and live file watching. A one time Pro upgrade priced at 34.99 USD unlocks the interactive sky map, the Wish List and visibility planning, the Statistics Dashboard, equipment management, star extraction and seeing analysis, and plate solving. Additional details and screenshots are available at https://www.macobservatory.com/meridian-deep-sky-imaging-catalog.

Built for reliability and respect for your files

Meridian is strictly read only. It does not modify, move, or rename your files, and its database can be rebuilt from source at any time. The goal is to provide a trustworthy catalog of record that reflects what is actually on disk. Because the object database ships with the app and visibility computations run locally, Meridian remains responsive and private whether you are at your desk or in the field.

A request for real world testing

Andrew welcomes feedback from imagers with substantial archives and unusual edge cases. If you maintain large libraries exceeding fifty thousand files, rely on external or networked drives, or use rare catalog designations and custom header fields, your input will help refine parsing and matching rules. Reports about header corner cases, performance across many volumes, and behavior with diverse capture software are especially helpful. The beta aims to validate Meridian across the wide range of workflows that exist in the community, so that the catalog view remains accurate, fast, and dependable over time.

What success looks like

Success for Meridian is straightforward. When you wonder whether you already have enough luminance on a target, which filters you are missing on a multi season project, or what you have shot with a particular rig, the answer should be one search away. When you plan the next clear night, the targets that fit your equipment and your sky should be obvious. And when you explore what you have captured across the years, you should be able to see the arc of your imaging with clarity and confidence, all from a single Mac application.

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