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"26038 results found.
- GRB 990123, new radio source
- GRB 990123: Optical Decay Slope
- GRB 990123 r-band photometry
- GRB990123, BeppoSAX-NFI X-ray afterglow detection
- Optical Observations of GRB 981220
- GRB981220
- GRB 981220 Optical observations
- GRB 981226 Optical Observations
- GRB981226 Optical Observations
- GRB 981226
- GRB981220 B, R and I band observations
- GRB 981220
- GRB 981220, radio observations
- GRB980425 Optical Follow-up
- GRB980703 Very Long Baseline Interferometry
- GRB980703: Radio transient
- GRB 980703: Spectrum of the proposed optical counterpart
- RXTE Observation of GRB 980706
- GRB980613 Optical Observations
- GRB980703 optical followup
- GRB 980613 Optical Observations
- GRB980613 Optical Observations
- GRB980613 BeppoSAX-NFI follow up
- GRB 980519
- GRB980515, BeppoSAX IAUC to be submitted
- SAX J0840.7+2248 Optical Observations
- GRB 980329 ROSAT observation
- GRB980326 X-ray Observations
- GRB980329, Fading IR counterpart to radio source
- GRB980329 sub-millimeter observations
- GRB980329 near-IR observations
- GRB980329 optical observations
- GRB980329 VLA observations
- GRB980329 optical observations
- Near-IR follow-up on GRB 971227
- GRB971227: Plaskett R-band observations
- GRB 971227: Optical clarifications
- GRB971227: Further CAHA R-band images