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"31632 results found.
- GRB980425: Radio Observations
- GRB 980425 optical observations
- GRB980326, optical observations
- GRB980326, optical observations
- GRB980329, Fading IR counterpart to radio source
- GRByymmdd, Announcement of automation
- GRB980326 IPN annulus
- GRB980329
- GRB980329 Keck K-band observations
- GRB980329 sub-millimeter observations
- GRB980329 IPN annulus
- GRB980329 optical observations
- GRB980329 near-IR observations
- GRB980329 optical observations
- GRB980326 optical observations
- GRB980326 optical observations
- GRB970508 SAO RAS optical observations
- GRB 971214: Redshift from Keck Observations
- Near-IR follow-up on GRB 971227
- GRB971214: Keck R & I-band Observations
- GRB 971227: Optical Observations
- Optical Observations of the GRB 971227 field
- GRB971227: Plaskett R-band observations
- GRB 971227: Optical clarifications
- GRB971227: LOTIS observations
- GRB971214: Optical Observations and Calibrations
- Optical Observations of GRB 971214 at Keck
- GRB 971024: Refined analysis by USNOFS Observations
- GRB 971024: USNO Observations
- GRB 970925: BATSE Localization
- IRAS 18119-1342 and the possible new SGR
- GRB 970228: Keck/LRIS Optical Observations