Check whether a source is already in the catalog
Enter a source name, coordinates, or both. Coordinates may be decimal degrees or sexagesimal.
Interactive sky distribution
Hover over a marker for source information. Drag to rotate and scroll to zoom.
Catalog statistics
Counts are calculated directly from the current catalog release. Multi-wavelength catalog counts represent unique CLAGN sources with a recorded match in each public survey.
Submit new targets or updates
Before submitting, use the duplicate checker. Submit one source through the form or upload a CSV for a source list.
To connect your form, edit config.js and replace googleFormUrl.
About the CLAGN Database
Overview
The Changing-Look AGN Database is a curated, community-oriented resource designed to facilitate the discovery, exploration, and follow-up of changing-look active galactic nuclei. It provides a unified interface for catalog exploration, duplicate checking, interactive sky visualization, access to public spectra, observing preparation, and community-driven catalog updates.
Features
- Interactive exploration of confirmed and candidate changing-look AGN.
- Name- and coordinate-based duplicate checking.
- Source-specific multiwavelength information organized by wavelength regime.
- Direct access to public spectra and external astronomical archives.
- Interactive sky maps and source visibility plots.
- Community submission of new sources and updates to existing entries.
Data Sources
The database combines literature-curated source information with cross-matched measurements and public resources from major astronomical surveys and archives. Detailed descriptions of the catalog construction, selection, validation, and multiwavelength associations are provided in the accompanying publication.
Citation
If you use the CLAGN Database in a scientific publication, presentation, or derived research product, please cite the accompanying catalog paper:
Camus & Panda (2026)
arXiv:2607.25839
The DOI, ADS bibliographic record, and journal publication link will be added after formal publication. Users should also cite the original discovery and classification papers for individual sources where appropriate.
Data Use Policy
The CLAGN Database is a curated community resource. If you use the catalog or substantial portions of its curated content in research, presentations, or derived products, please cite the CLAGN Database and the associated publication. The public interface is intended for interactive exploration; direct bulk-download files are not distributed through this website. Bulk redistribution of the catalog without permission is discouraged.
For data or catalog requests and collaboration inquiries, contact Swayamtrupta Panda at swayamtrupta.panda@noirlab.edu.
Acknowledgements
Supported by the International Gemini Observatory, a program of NSF NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the U.S. National Science Foundation, on behalf of the Gemini partnership of Argentina, Brazil, Canada, Chile, the Republic of Korea, and the United States of America.
Contact
Questions, corrections, bug reports, collaboration inquiries, and submissions of new changing-look AGN are welcome.
Swayamtrupta Panda
swayamtrupta.panda@noirlab.edu
Version
CLAGN Database v1.0.0
Last updated: July 2026