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Firefly Sessions

Firefly is a browser-based astronomy application for viewing images, tables, and supported archive data. The available Firefly image and features are deployment-specific.

Launch Firefly

  1. Sign in to the Science Portal.
  2. In Launch New Session, choose Firefly, select an image containing the software you need, and launch the Session.
  3. Wait for it to start under Active Sessions, then open its application link.

Save your work under /arc before using the Session's delete control in the portal. Closing the browser tab does not stop the Session. See Get started for account, storage, and cleanup steps.

Launch from the command line (optional)

Install the client before using these commands.

canfar login cadc
canfar image ls --kind firefly
canfar create firefly IMAGE_NAME --name archive-exploration

The Science Portal provides the same Session Kind. Monitor the Session and open it when ready:

canfar ps --all
canfar info SESSION_ID
canfar open SESSION_ID

If a Session remains Pending, inspect canfar events SESSION_ID; see batch troubleshooting.

Load data

Use the paths and URLs supported by the selected Firefly image. A common workflow is to place data under mounted storage:

/arc/home/<user>/          personal persistent files
/arc/projects/<project>/   shared project files, when available
/scratch/                  temporary staging

For a remote object in a configured VOSpace Service, transfer it explicitly before opening it in a path-oriented application:

canfar data cp IDENTIFIER:/path/to/image.fits local:/scratch/image.fits

Use Firefly's own archive or URL features only as documented by the selected image. Do not assume that a VOSpace URL, archive endpoint, table format, or remote service is enabled on every deployment.

Save figures, tables, regions, and other products under /arc or a persistent VOSpace Service. /scratch is deleted when the Session ends. See Storage and Data transfers.

Typical workflow

  1. Open a FITS image, table, or archive result supported by the image.
  2. Inspect image metadata and WCS before interpreting the display.
  3. Use the image, table, and catalogue tools provided by the selected Firefly version.
  4. Export products and record the source path, image reference, and relevant display settings.

For analysis that must be rerun, use Python or a headless Session and keep Firefly for visual inspection.

Troubleshooting

  • If the image is unavailable, check canfar image ls --kind firefly and ask the platform operator about the deployment's catalogue.
  • If a local file does not open, verify its path and permissions or stage it to /scratch with canfar data cp.
  • If a remote URL fails, confirm that the image supports that endpoint and that the Session can reach it; do not embed credentials in the URL.
  • If the browser disconnects, check canfar ps --all and canfar info before restarting the Session.

See Support when the cause remains unclear.