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"19565 results found.
- GRB 180721A: Swift/UVOT Upper Limits
- FRB 180714: MASTER optical inspection of the Fast Rado Burst Transient
- ANTARES neutrino Alert180713.02: MASTER optical observation
- GRB 180720B: Swift-BAT refined analysis
- GRB 180721A: Enhanced Swift-XRT position
- GRB 180721A: Swift detection of a burst
- GRB 180720C: Swift/UVOT Upper Limits
- GRB 180720C: Enhanced Swift-XRT position
- GRB 180720C: Swift detection of a burst or possible Galactic Transient
- GRB 180720B : TSHAO optical observations
- GRB 180715A: MASTER optical observation
- GRB 180720B: Kanata 1.5m optical/NIR observation
- GRB 180720B: Swift detection of a burst
- GRB 180715A: Gemini imaging upper limits
- GRB 180715A: Swift/UVOT Upper Limits
- Swift detects a flare from AX 1631.9-4752
- GRB 180718A: Swift ToO observations
- GRB 180718B: Swift ToO observations
- GRB 180715A: COATLI Optical Observations
- GRB 180715A: Swift-XRT observations
- GRB 180715A: GOTO optical limits
- GRB 180715A: LCO Sutherland possible optical candidate
- GRB 180715A: Swift-XRT observations
- IceCube-171106A: MASTER optical observation
- GRB 180705A: OSN observations
- GRB 180709A: Swift/UVOT Upper Limits
- GRB 180709A: Optical limits
- GRB 180709A: COATLI Optical Observations
- GRB 180709A: Enhanced Swift-XRT position
- GRB 180703A: Swift-XRT afterglow detection
- GRB 180709A: Swift detection of a burst
- GRB 180705A: RTT150 optical upper limit
- Trigger 846740: Swift trigger near NGC5055
- IPN Triangulation of GRB 180703A
- GRB 180706A: GOTO optical limits
- GRB 180706A: TSHAO optical observations
- GRB 180706A: Swift/UVOT Detection
- GRB 180706A: Enhanced Swift-XRT position
- GRB 180705A: TSHAO optical upper limit
- GRB 180705A: Swift/UVOT Upper Limits
- GRB 180705A: RATIR Optical Observations
- GRB 180706A: COATLI Optical Detection
- GRB 180706A: Swift detection of a burst with optical counterpart
- IPN Triangulation of GRB 180703B
- GRB 180705A: Enhanced Swift-XRT position
- GRB 180705A: Swift-XRT observations
- GRB 180703A: Swift/UVOT Upper Limits
- GRB 180704A: Swift/UVOT Upper Limits
- GRB 180704A: Enhanced Swift-XRT position
- GRB 180704A: Swift-XRT observations
- GRB 180704A: MASTER optical observation
- GRB 180703A: Tiled Swift observations
- GRB 180630A: Swift/UVOT Detection
- GRB 180630A: Fermi GBM detection
- GRB 180630A: Enhanced Swift-XRT position
- GRB 180630A: Swift detection of a burst with an optical counterpart
- GRB 180626A: TSHAO optical upper limit
- GRB 180626A: RATIR Optical Observations
- IPN Triangulation of GRB 180626C (short)
- IPN Triangulation of GRB 180626B (short)
- GRB 180626A: KAIT Optical Upper Limit
- GRB 180626A: COATLI Optical Detection
- GRB 180626A: Swift/UVOT Detection
- GRB 180626A: RATIR Optical Detection
- GRB 180626A: ISON-MN optical observations
- GRB 180626A: Enhanced Swift-XRT position
- GRB 180626A: Swift detection of a burst with an optical counterpart
- GRB 180624A: RATIR Optical Observations
- GRB 180624A: LBT/MODS redshift measurement
- GRB 180613A: LCO Afterglow detection
- GRB 180624A: GROND observations
- GRB 180624A: MITSuME Okayama optical upper limits
- GRB 180624A: Swift/UVOT Upper Limits
- GRB 180624A: Enhanced Swift-XRT position
- GRB 180624A: Swift detection of a burst
- GRB 180623A: Swift/UVOT Detection
- GRB 180623A: Enhanced Swift-XRT position
- GRB 180623A: Swift detection of a burst
- GRB 180620B: Swift/UVOT Detection
- GRB 180620A iTelescope observation
- GRB 180613A: Afterglow confirmation and added photometry
- GROND observations of GRB 180620B
- GROND observations of GRB 180620A
- GRB 180620B: Enhanced Swift-XRT position
- GRB 180620A: Xinglong-2.16m optical observations
- GRB 180618A: Swift/UVOT Detection
- GRB 180618A: TSHAO optical upper limit
- GRB 180620B: Swift detection of a burst with an optical counterpart
- GRB 180620A: COATLI Detection and Light Curve
- GRB 180620A: Swift/UVOT Detection
- GRB 180618A: Xinglong-2.16m optical upper limit
- GRB 180620A: Enhanced Swift-XRT position
- GRB 180620A: ISON-MN afterglow confirmation
- GRB 180620A: RATIR Optical Afterglow Detection
- GRB 180620A: Swift detection of a burst with an optical counterpart
- GRB 180618A: Enhanced Swift-XRT position
- GRB 180618A: Swift detection of a burst with an optical counterpart
- GRB 180614A: AbAO optical observations
- GRB 180614A: Swift/UVOT Upper Limits
- GRB 180614A: NOT optical upper limits