TheSky with Gaia DR3 Star Catalog Support

Be sure to maintain your software subscription to get access to the latest software installers and updates! What is Gaia DR3?
Why Use Gaia Data?
Minimum System Requirements
Gaia FAQs
How can I install the latest version of TheSky?

What is the Gaia Data Release 3?

The European Space Agency’s Gaia satellite observation mission continues to release updates the largest and most accurate star catalog ever produced, with precision astrometric, photometric and spectroscopic measurements on more than 1.8 billion stars. The current officially release catalog data is called Gaia Data Release 3 (DR3).

TheSky Professional Edition version 10.5.0 build 13479 and later (released in November, 2022) displays Gaia star positions with milliarcsecond accuracy, and includes G/BP/RP mean magnitudes, spectral class, stellar temperature, and proper motion…that means TheSky can show you the stars’ distance from Earth, in light years, for up to 1.8 billion stars!

Why do I need Gaia stars?

In a nutshell, the more accurate the star catalog’s positions, the more accurate the scientific measurements based on these stars will be.

Whether you’re using TheSky’s Image Link to perform an Automated Pointing Calibration and produce a TPoint Super Model that improves your telescope’s pointing and tracking, running a script that finds the astrometric position of double star companions, or studying dynamic nature of stellar proper motion for the past thousand years, you can count on the Gaia catalog to provide the best results.

Gaia DR3 Database Details

The native Gaia DR3 dataset contains over 1.2 terrabytes (TB) of star data. The entire database can be downloaded from the Gaia archive page.   When the complete dataset is present, TheSky Professional Edition’s Sky Chart displays every star from the Gaia catalog and can access the accompanying star “metadata.”

If you do not need the entire dataset, TheSky Professional Edition offers two different Gaia star catalog subsets that should suit the needs of even the most ardent astronomer.

  • Large Gaia Subset: The larger Gaia subset contains the RA, Dec, magnitude, spectral class and proper motion on 1.806 billion stars.
  • Small Gaia Subset: The smaller Gaia subset contains about 100 million stars that are equally distributed across the celestial sphere and is ideal for determining the astrometric solution (or “plate solve”) for photos as small as about 3 arc minutes across.

Table 1: Gaia DR3 Subset Databases

Catalog NameNumber of StarsLimiting
Size (GB)
Large Gaia Subset1.806 billion~19114
Small Gaia Subset~100 millionn/a* 5.8

*Not applicable. TheSky’s Small Gaia Subset database was created to have a relatively equal distribution of stars across the entire celestial sphere. This ensures that astrometric solutions can be found in photos acquired using a broad range of optical systems, and taken anywhere in the sky. While there are some 18 magnitude stars in certain regions, this is not a limiting magnitude for this subset.

Minimum System Requirements

  • TheSkyX version 10.5.0 build 13479 and later is required to display Gaia data.  Choose the About TheSky command (Help menu on Windows/Linux, TheSkyX menu on macOS) to make sure you have a compatible version installed.  If not, click Help > Check for Updates and install the latest daily build.
  • The Databases module SSD Version 3 and later includes the small and large Gaia subset databases.
  • The small Gaia subset can be downloaded here (log in required).


Q. I already own TheSky Professional or TheSky Imaging and my subscription is up to date. How can I get the Gaia star catalog?

A. First, install the latest daily build from My account > My Downloads. Next, download the Gaia subset and follow the instructions on the Gaia subset download page to view them. The Large Subset with 1.8 billion stars is available in the Databases module.

Q. How do I configure TheSky to use the Gaia data?

A. Please see TheSky User Guide for details.

Q. Does TheSky support the Gaia Data Release 3 (DR3)?

A. Yes. TheSky Professional Edition version 10.5.0 build 13479 and later (released in November, 2022) supports DR3.

Q. I have a version of TheSky installed (versions 10.5.0 build 12978 and earlier) with no Gaia support. How to I get Gaia support?

Q. What should I do with the Gaia DR2 subset files?

A. The Gaia DR3 subset database supersedes the the Gaia DR2 subset. Once DR3 is installed, you can safely delete the DR2 database file (named GAIA Subset.plot in TheSky’s Resources/Professional/Core Databases/Gaia.

A. If you have an older version of TheSky installed that does not support Gaia, and want to install a version of TheSky that includes Gaia support, first log in to and renew your subscription. After renewing your subscription, you’ll have access to the latest full installer and the latest updates. The steps below describe two ways to install the latest version of TheSky with Gaia star catalog support.

Download and Install the Latest TheSky Pro Full Installer
  1. Determine the folder where TheSky was originally installed on your computer.
    • macOS: TheSky is always installed to the computer’s Applications folder.
    • Linux: TheSky AMD64 is installed to a folder named TheSky on the Desktop.
    • Windows: By default, TheSky is installed to the computer’s C:\Program Files (x86)\Software Bisque\TheSkyX Professional Edition folder. Otherwise, use Windows File Explorer to search for the file named “TheSkyX.exe” and note the name of the folder where this file resides.
  2. Before installing the later version of TheSky, backup TheSky’s settings first as described in this article.
  3. Click My account > My downloads, and download the latest TheSky Full Installer for your operating system. The latest full installer (about 6 GB in size) includes the Gaia star catalog.
  4. Run the latest full installer.
    • macOS: Drag and drop TheSky to the Applications folder.
    • Linux: When prompted, select TheSky folder on the computer’s Desktop for the destination.
    • Windows: When prompted, select the same installation folder as the existing version of TheSky (as determined in Step 1 above). Your existing TheSky settings will be preserved.


Download the Latest Daily Build and the Gaia Subset Separately
  1. Click My account > My downloads, and download the latest TheSky Daily Build Installer for your operating system.
  2. Download the Gaia DR3 Small Subset and follow the Installing the Gaia DR3 Subset instructions on the download page.