GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"12 results found.
- GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
- GRB 231017A: 1.3m DFOT Optical upper limit
- GRB 231017A: Swift/UVOT Upper Limit
- GRB 231017A: GOTO optical upper limits
- GRB 231017A: JinShan optical upper limit
- GRB 231017A: Las Cumbres optical upper limit
- GRB 231017A: LCOGT Optical Upper Limits
- GRB231017A: GROWTH-India upper limits on the optical afterglow
- GRB 231017A: Fermi GBM Detection
- GRB 231017A: Swift-XRT observations
- GRB 231017A: Swift ToO observations
- GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst