GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"- GRB test
- GRB test
- GRB bar
- GRB test
- GRB Main test
- GRB Main test
- GRB Test test tes
- XTR This is just a test for Security Research
- [DRILL] Super-Kamiokande test
- GRB 260704A: test
- GRB 260704A: test
- GRB 260704A: VDP reachability check [20260706T063208Z]
- GRB foo
- GRB foo
- GRB 260704A: VDP authorized test (self-spoof, please disregard) [20260706T063208Z]
- GRB 260704A: VDP reachability check [20260706T063208Z]
- GRB 260704A: VDP authorized test (self-spoof, please disregard) [20260706T062346Z]
- GRB 260704A: VDP reachability check [20260706T062346Z]
- GRB test: this is a test
- [TEST] Super-Kamiokande finds a supernova in the Milky Way Galaxy
- GW test test test
- GW test test test
- GW Test GCN circular submission still works
- GRB test
- GRB 250115: A GRB during the coffee break at AAS
- GRB test from AAS
- GRB test
- GRB 000000A Testing - Have a good day!
- GRB 123456Z courey testing
- GRB Test
- GRB testing
- GRB iOS chrome again
- grb123: iOS Chrome testing
- GRB testing iOS
- GRB test from Chrome iOS
- GRB testing
- GRB Testing for Kafka
- GRB Testing
- GRB foobar
- GRB foobar test
- GRB testing 3
- GRB testing 2
- GRB testing
- GRB test 4
- GRB test 3
- GRB test 2
- GRB test
- GRB foobar
- GRB foobar
- LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
- LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
- GRB foobar
- GRB foobar
- PKS2326-505, millimeter wavelength flare, transient
- GRB foo 3
- GRB foo 2
- GRB foo
- GRB foo
- GRB foo
- GRB foo
- GRB test
- GRB foo
- GRB foobar
- GRB foobar
- GRB foobar
- GRB foobar
- GRB foobar
- GRB test
- MAGIC test
- GRB test
- GRB foo
- Test GCN GW submission
- GRB test 2
- GRB test
- GRB test
- Test GW GCN hermes submission 2
- Test GW GCN hermes submission
- Test GW GCN hermes submission
- A GRB test
- TEST GW GCN hermes submission
- GRB 170817A: an awesome GCN Circular
- VIRT optical transient detection
- GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
- GRB 230307A: iTelescope optical upper limit (likely)
- GRB 230414B: Montarrenti Observatory late time optical afterglow detection
- IceCube-230416A: IceCube observation of a high-energy neutrino candidate
- Fermi trigger No 703284533: Global MASTER-Net observations report
- GRB 230414B: Lulin 40cm-SLT optical limit
- GRB 230414B: Bassano Bresciano Observatory optical observations
- GRB 230414B: Redshift from OSIRIS/GTC
- GRB 230414B: AbAO optical observations
- GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
- GRB 230414B: Swift-XRT refined Analysis
- GRB 230414B: Dabancheng/GHOST optical observations
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
- GRB 230414B: slow optical light curve decay
- GRB 230414B: SAO RAS optical observations
- GRB 230414B: Enhanced Swift-XRT position
- GRB 230414B: 1.3m DFOT Optical observations
- Fermi GRB 230414A: Global MASTER-Net observations report