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').
12 results found.
- GRB 211221A: No V & R detection, KAO telescope
- GRB 211221A: Swift/UVOT Upper Limits
- Fermi GBM Sub-Threshold Detection of GRB 211221A
- GRB 211221A: Swift-BAT refined analysis
- GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
- GRB 211221A: Swift-XRT refined Analysis
- GRB 211221A: BOOTES-4/MET optical upper limit
- GRB 211221A: MeerLICHT optical limits
- GRB 211221A: NOT optical limits
- GRB 211221A: Enhanced Swift-XRT position
- Swift GRB 211221A: Global MASTER-Net observations report
- GRB 211221A: Swift detection of a burst