Collect and curate your astronomical images. Search 10+ professional image archives simultaneously. Create master bias, dark and flat frames. Calibrate, register, stack and adjust your FITS, XISF (PixInsight), SBIG and RAW images, all nondestructively.


• A flexible hierarchy: create as many libraries as you wish and keep your images organized with albums, smart albums and folders. Let Observatory keep track of your images, without copying, moving or altering them.

• Observatory automatically normalizes the image metadata in its libraries, categorizes images, and supports metadata bulk editing. You can also manually tag, rate, color code, reject or archive images. And you can add notes or attach important reference material to your images and albums.

• A nondestructive preprocessing workflow without the hassle of intermediate files.

⁃ Calibration
⁃ Cosmetic Correction
⁃ Binning
⁃ Debayering
⁃ Background Neutralization
⁃ Color Balance
⁃ Flatten Background
⁃ Chromatic Align
⁃ Register
⁃ Normalize
⁃ Stack
⁃ Resize
⁃ Rotate
⁃ Crop

• Quick Look & Spotlight: display thumbnails, previews and metadata of FITS, XISF and SBIG images in Finder and other applications. Observatory also helps your Mac index the metadata, so you can quickly find your images by dimensions, exposure time, focal length, detector temperature, right ascension, declination and more.

• Virtual Observatory: search 10+ professional archives simultaneously and download research images from

⁃ European Southern Observatory
⁃ W. M. Keck Observatory
⁃ Gemini Observatory
⁃ Hubble Space Telescope
⁃ Spitzer Space Telescope
⁃ WISE Space Telescope
⁃ Palomar Transient Factory
⁃ SkyMapper Southern Sky Survey
⁃ Two Micron All Sky Survey
⁃ Sloan Digital Sky Survey
⁃ Digitized Sky Survey

• Overlay the 3.5 million stars, galaxies and other objects of the Messier, NGC/IC, Tycho-2 and PGC 2003 catalogs, or use the UCAC4 and USNO-A2.0 catalogs for an additional 500 million stars.

• Plate Solving: if some of your images lack the information to relate image pixels to actual sky coordinates, Observatory’s plate solver will help you find the best match, using its built-in catalogs, as well as the UCAC4 and USNO-A2.0 catalogs.

• Measure: image statistics, aperture photometry, PSF fitting and astrometry.

• Open FITS, XISF and SBIG images at full bit depth in Acorn, with help of our Acorn plugin.

For more information, please watch the videos and read the documentation on our website!


If you have any feedback or questions, we’d love to hear from you! You can reach us by email at

If Observatory empowers you, we would appreciate an App Store review. Your review will help other people find Observatory.

Thank you!

What's New

Version 1.2.1

• “Forums” in the Help menu provides quick access to the new Code Obsession Forums on our website. Please join if you want to discuss the use of Observatory and related issues with us or other users.
• Resolved various bugs that conspired against the star detector and plate solver.
• The Astrometric Match sheet has a new Automatic Detection Sensitivity setting, a Help button and when it fails to find a solution, the plate solver now lets you quickly retry it with adjusted settings.
• Fixed macOS High Sierra specific issues.

For more details, please see the longer release notes which are available from the Help menu in the app.

If you have any feedback or questions, we’d love to hear from you! You can reach us by email at

If Observatory empowers you, we would appreciate an App Store review. Your review will help other people find Observatory.

Customer Reviews

It Was Worth the Wait


I purchased Observatory last October hoping to be able to use it on my 6-year-old MacBook Pro to process deep sky astrophotos from my Canon EOS 60 Da. After much fiddling around, it was clear that the program was buggy and would not properly align and stack properly, if at all. I contacted the developer by email and he responded quickly asking for details. That began a chain of communications during which the application would be updated, bugs fixed and I would try it again and send my comments and often result to the developer. With the latest update, 1.0.8, the program now aligns and stacks properly. There is very little post processing available in this application and it is not intended for that. Post processing must be done in a separate program such as Photoshop. The online instruction manual is also not complete as of yet but it is progressing. There are many other features of this application that I have not yet tried. My main reason for purchasing it was to have a Mac program that would align and stack astrophotos and Observatory now does this well.

My rating of 5 stars may seem excessive but I am considering the quality of the technical support, relative price and paucity of other similar applications for the Mac. I also expect that Observatory will continue to improve.


Code Obsession LLC
55.2 MB
Age Rating
Rated 4+
© 2016–2018 Code Obsession, LLC


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.