Astronomical Coordinate Converter
Convert sky coordinates between equatorial, Galactic and ecliptic systems. Choose the reference settings and download the new coordinates.
How can I convert astronomical coordinates between reference frames?
Enter a CSV with longitude and latitude in decimal degrees, plus an optional name column. Choose ICRS, FK5, FK4, Galactic or barycentric true ecliptic source and target frames. FK4, FK5 and ecliptic frames accept explicit J or B equinoxes. The service converts the directions and returns a labelled CSV, using right ascension and declination for equatorial longitude and latitude.
Your result
A little clarity, right here.
Start with your own content or load the example. Your result will appear here.
Three simple steps
How to use Astronomical Coordinate Converter
Choose a local file or enter the coordinate table and review the processing notice.
Select the bands, image plane, crop bounds or coordinate frames you need.
Run the isolated service, review the report and download the result.
Common questions
Good to know
Understand the result.
Keep the original.
Is this tool free, and are my files uploaded?
This tool is free with no account required. When you run the tool, your input goes to a separate processing service. Temporary files are deleted when the job ends. You can download the result to your device.
What are the limits and details?
Up to 10,000 coordinate rows and 500,000 input characters; the preview shows 500 rows. Longitudes must be −360 to 360 degrees, latitudes −90 to 90, and equinoxes from 1800 through 2100. This is a direction-only frame/equinox transformation. It does not propagate proper motion or observing epoch, or apply distances, velocities, observer locations, refraction or atmospheric corrections.