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"- GRB980425: optical obs.
- GRB980425: Radio Observations
- GRB 980425 optical observations
- report on BSAX observations of GRB980425
- GRB 980425 optical observations
- GRB 980329 ROSAT observation
- GRB980326 X-ray 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 near-IR observations
- GRB980329 optical observations
- GRB980329 infrared observations
- GRB980329 optical observations
- GRB980326 optical observations
- GRB980329 optical observations
- GRB980329 VLA observations
- GRB980329 near IR observations
- GRB980329 optical observations
- GRB980329 optical observations
- GRB980329 optical observations
- GRB980326 optical observations
- GRB980326 optical observations
- GRB980326 optical observations
- GRB980326 optical observations
- GRB970508 SAO RAS optical observations
- Optical Observations of GRB 970508
- 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
- Optical Observations on GRB 971227
- GRB971227: Plaskett R-band observations
- GRB 971227: Optical clarifications
- Optical Observations for GRB 971227
- GRB971227: Further CAHA R-band images
- GRB971227: LOTIS observations
- GRB 971227: CAHA R-band images
- GRB 971227: Optical observations
- GRB971214: Optical Observations and Calibrations
- Sub-millimeter Observations of GRB 971214 at the JCMT
- GRB 971214: EUVE Observations
- GRB 971214: Redshift from Keck Optical Observations
- GRB 971214: Redshift from Keck Optical Observations
- GRB 971214: Apache Point Observatory Optical Observations
- GRB 971214: KPNO Optical Observations
- Optical Observations of GRB 971214 at Keck
- GRB 971214: Optical Observations
- Radio Observations of GRB 971214 at the VLA
- GRB 971214: USNOFS Observations Summary
- GRB 971024: KPNO Optical Observations Summary
- GRB 971024: Refined analysis by USNOFS Observations
- GRB 971024: KPNO Optical Observations
- GRB 971024: USNO Observations
- GRB 970925: BATSE Localization
- IRAS 18119-1342 and the possible new SGR
- Possible new SGR from US Naval Observatory
- RXTE Observations of SGR 1814-13
- GRB 970828: Palomar Observations
- GRB 970228: Keck/LRIS Optical Observations