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.
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"
6098 results found.
- GRB 181201A: Fermi-LAT detection
- GRB 181201A: iTelescope optical afterglow detection
- GRB 181201A: Swift-XRT afterglow detection
- GRB 181126A: No Ks-band afterglow detection with Keck I
- GRB 181126A: Swift-XRT refined Analysis
- GRB 181126A: Fermi GBM observation
- GRB 181125A: Fermi GBM observation
- GRB 181123B: Swift-XRT refined Analysis
- GRB 181120A: Fermi GBM observation
- GRB 181120A: Fermi-LAT detection
- Swift Trigger 872470: further Swift analysis
- GRB 181110A: optical observations in Chilescope observatory
- GRB 181110A: Swift-XRT refined Analysis
- GRB 181103A: Swift-XRT refined Analysis
- GRB 181030A: Swift-XRT refined Analysis
- GRB 181030A: SAO RAS optical observations
- GRB 181028A: Fermi GBM observation
- GRB 181028A: Fermi-LAT detection
- GRB 181027A: Fermi GBM detection
- IceCube-181023A: HAWC follow-up
- Fermi-LAT Gamma-ray Observations of IceCube-181023A
- GRB 181022A: Swift-XRT refined Analysis
- GRB 181023A: Swift-XRT refined Analysis
- GRB 181020A: Global MASTER Net OT observations
- GRB 181020A: Swift-XRT refined Analysis
- GRB 181020A: Fermi GBM detection
- GRB 181020A: Fermi-LAT detection
- Fermi-LAT Gamma-ray Observations of IceCube-181014A
- GRB 181013A: Swift detection of a probable burst
- GRB180913A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 558557292)
- GRB 181010A: Fermi GBM observation
- GRB 181010A: Swift-XRT refined Analysis
- GRB 181003A: Swift-XRT afterglow detection
- GRB 181002A: Swift-XRT refined Analysis
- GRB 180930A: Swift-XRT refined Analysis
- GRB 180925A: Swift-XRT refined Analysis
- GRB 180924A: Swift-XRT refined Analysis
- GRB 180923B: Fermi GBM detection
- GRB 180914B: Swift-XRT afterglow detection
- GRB 180914B: Fermi-LAT detection
- GRB 180914A: Swift-XRT observations
- GRB 180914A: Fermi GBM detection
- GRB 180914A: Fermi-LAT detection
- IceCube-180908A: CALET Gamma-Ray Burst Monitor upper limits
- Fermi-LAT Gamma-ray Observations of IceCube-180908A
- INTEGRAL observation of IceCube-180908A
- IceCube-180908A: HAWC follow-up
- GRB 180905A: Swift-XRT refined Analysis
- GRB 180904A: Swift-XRT refined Analysis
- GRB 180904A: SAO RAS optical observations
- GRB 180904A: OSN observations
- GRB 180904A: NOT optical observations, candidate host galaxy
- GRB 180829A: Swift-XRT observations
- GRB 180828A: Swift-XRT refined Analysis
- GRB 180828A: Fermi GBM observation
- GRB 180823A: Swift-XRT refined Analysis
- GRB 180821A: Swift-XRT refined Analysis
- GRB180806A: confirmation of the X-ray afterglow
- GRB 180818B: Swift-XRT refined Analysis
- GRB 180818B: Fermi GBM observations
- GRB 180818A: Swift-XRT refined Analysis
- LIGO/Virgo GW170817: A steep decline in the radio light curve and prediction for the X-rays
- Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
- GRB 180812A: Fermi GBM detection
- GRB 180812A: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 180809B
- GRB 180809B: Swift-XRT refined Analysis
- GRB 180809B, Swift-BAT refined analysis
- Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
- GRB 180809A: Fermi GBM observation
- GRB 180809A: iTelescope optical limit
- GRB 180809A: Swift-XRT afterglow detection
- GRB 180806A: NOT optical observations
- GRB 180806A: Swift-XRT afterglow detection
- GRB 180806A: Fermi GBM detection
- GRB 180805A: Swift-XRT refined Analysis
- GRB 180805B: Swift-XRT refined Analysis
- GRB 180805B: Fermi GBM detection
- GRB 180728B: Fermi GBM detection
- GRB 180728A: Fermi GBM observation
- GRB 180728A: Swift-XRT refined Analysis
- GRB 180727A: Swift-XRT refined Analysis
- GRB 180727A: Fermi GBM observation
- GRB 180723A: Fermi GBM detection
- GRB 180722A: Swift-XRT observations
- GRB 180718B: Swift-XRT observations
- GRB 180718A: Swift-XRT observations
- GRB 180720C: Swift-XRT refined Analysis
- GRB 180721A: Swift-XRT refined Analysis
- GRB 180720C: Fermi GBM observation
- GRB 180706A: OSN detection
- GRB 180720B: Swift-XRT refined Analysis
- GRB 180720B: Fermi GBM observation
- GRB 180720B : Fermi-LAT detection
- GRB 180720A: Fermi GBM observation
- GRB 180718B: Fermi GBM detection
- GRB 180718B: Fermi-LAT detection
- GRB 180718A: Fermi GBM detection
- GRB 180715A: Swift-XRT observations
- GRB 180715A: Fermi GBM detection