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"3037 results found.
- GRB 160804A: Swift detection of a burst
- GRB 160714A: MASTER early optical observations
- GRB 160714A: Swift-XRT observations
- GRB 160712A: Swift-XRT observations
- GRB 160625B: Global MASTER-Crimea prompt optical emission detection (fwd)
- GRB 160705A/MAXI J0748-149: MAXI/GSC detection
- GRB 160629A: AbAO optical observations
- GRB 160525B: Mondy optical upper limit
- Swift detection of SGR 1935+2154
- GRB 160521B: Fermi-LAT detection
- GRB 160521B: Fermi GBM detection
- GRB 160509A: VLA Detection
- GRB 160509A Gemini North candidate afterglow
- GRB 160509A: Swift-XRT afterglow detection
- GRB 160506A: IRSF upper limits
- VERITAS rapid follow-up observations of IceCube event 160427A
- MASTER search for counterpart to the IceCube event 67093193 (run 127853)
- LIGO Virgo G211117: Additional MWA Observations
- GRB 160409A found in Swift BAT ground analysis
- IPN Triangulation of GRB 160406A (short/hard)
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160303A SMA observation
- GRB 160227A: McDonald 0.8m Detection
- GRB 160227A: MAXI/GSC detection
- GRB 160225A: TSHAO optical upper limit
- Konus-Wind observation of GRB 160220B
- GRB 160220A: MASTER-Amur observations
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160206A: MAXI/GSC detection
- GRB 160203A: Enhanced Swift-XRT position
- GRB 160203A: GROND Afterglow Candidate
- GRB 160203A: Swift detection of a burst
- GRB 160123A: Swift-BAT refined analysis
- IPN Triangulation of GRB 151231A
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- GRB 160107A: MAXI/GSC detection
- IPN Triangulation of GRB 151225A (short/hard)
- LIGO/Virgo G211117: Summary of Pan-STARRS transients
- GRB 160104B: MAXI/GSC detection
- LIGO/Virgo G211117: LOFAR follow-up
- LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
- LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
- IPN Triangulation of GRB 151227B
- V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
- LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
- LIGO/Virgo G211117: iPTF Optical Transient Candidates
- GRB 151228B: Fermi GBM observation
- LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
- LIGO/Virgo G211117: Optical follow-up with Kanata telescope
- GRB 151228B: Swift detection of a burst with an optical detection
- GRB 151215A: TSHAO optical observations
- Swift detection of 4U 1850-03
- GRB 130831A: MASTER early OT detection and LC
- GRB 151205B: MASTER-NET early optical observations
- GRB 151205A: Swift detection of a burst
- GRB 151127A iTelescope observation
- GRB GRB 151118A: MASTER-NET optical observations
- GRB 151111A: GROND marginal detection of a afterglow candidate
- GRB 151111A: LCOGT-FTS afterglow observations
- GRB 151027A: Mondy optical observations
- GRB 150910A: CrAO optical observations
- LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
- GRB 151022A: MASTER-Ural observations
- GRB 151006A: Mondy optical upper limit
- Swift Trigger 658045 is not a GRB
- LIGO/Virgo G184098: Further VST-ESO PARANAL observations
- LIGO/Virgo G184098: VST-ESO PARANAL observations
- LIGO/Virgo G184098: Swift follow-up observations
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150907B: Swift-BAT refined analysis
- GRB 150907B: Enhanced Swift-XRT position
- GRB 150907B: GROND Upper Limits
- GRB 150907B: Swift-XRT observations
- GRB 150907A: Swift-XRT observations
- GRB 150907A: MAXI/GSC detection
- ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
- GRB 150902A: MASTER-SAAO optical observations
- Konus-Wind observation of GRB 150902A
- GRB 150831B: MASTER-IAC early optical observations
- IPN Triangulation of GRB 150824A
- Konus-Wind observation of GRB 150818A
- GRB 150821A: Swift detection of a burst with an optical afterglow
- GRB 150819A: Swift-BAT refined analysis
- GRB 150819A: Swift detection of a burst
- Fermi GBM trigger 150806450 is not a GRB
- GRB 150801B: Enhanced Swift-XRT position
- Trigger 649113: Swift detection of SGR 1E 1841-045
- Fermi Gamma-ray Burst Monitor triggers that are not GRBs
- GRB 150710B refined analysis
- GRB 150710B detected in ground analysis of BAT data
- GRB 150626B, Swift-BAT refined analysis
- V404 Cyg: MASTER Swift, Integral alert observations
- GRB 150622A: MAXI/GSC detection
- GRB 150527A: Swift-XRT refined Analysis
- GRB 150527A: Fermi GBM observation
- GRB 150518A: Mondy optical observations
- GRB 150430A: MAXI/GSC detection
- GRB 150413A: CrAO optical observations
- GRB 150424B: MAXI/GSC detection
- GRB 150424A: Swift detection of a short burst