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"3762 results found.
- GRB 140528A: Fermi GBM Detection
- Konus-Wind observation of GRB 140529A
- GRB 140529A found in ground analysis of BAT slew data
- Swift detection of SFXT IGR J17544-2619
- IPN Triangulation of GRB 140523A
- Swift trigger 599860 probably not real
- GRB 140521A: AAO optical observations
- GRB 140518A: P60 i-/z-band detections
- GRB 140515B: MAXI/GSC detection
- GRB 140512A: Mondy optical detection
- GRB 140512A: MASTER optical observations
- GRB 140509B: MAXI/GSC detection
- GRB 140428B: Fermi GBM observation
- Trigger 597570: Swift detection of SGR 1806-20
- GRB 140428A: Keck detection of a red optical afterglow candidate
- GRB 140423A: MITSuME Akeno Optical observation
- Konus-Wind observation of GRB 140416A
- Swift Trigger 595345 is not an astrophysical source
- Swift trigger 594286: Is likely a noise trigger
- Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
- Konus-Wind observation of GRB 140330A
- Konus-Wind observation of GRB 140329A
- Fermi Gamma-ray Burst Monitor trigger 417486540 / 140326020 is not a GRB
- GRB 140226A/iPTF14yb: Mondy optical observations
- IPN Triangulation of very intense GRB 140320D
- GRB 140320A: Swift-BAT refined analysis
- GRB 140320C: Swift-XRT detection of the X-ray afterglow
- GRB 140320A: Fermi GBM observations suggest a short GRB
- GRO J1744-28: Fermi GBM observation
- IPN Triangulation of GRB 140308A
- GRB 140304A: VLA Detection
- GRB 140304A: Swift-BAT refined analysis
- GRB 140304A: Enhanced Swift-XRT position
- GRB 140304A: Swift detection of a burst
- Konus-Wind observation of GRB 140215A
- Trigger 586482: Swift detection of GROJ1744-28
- GRB 140209A: Swift-BAT Spectral lag analysis
- GRB 140209A: Swift detection of a burst
- GRB 140129B: MASTER OT early light curve
- GRB 140129A: P60 optical afterglow detection
- GRB 140103A: AAO optical afterglow candidate
- Swift-BAT trigger 582894 is HR 1099 (Flare star)
- GRB 140103A: Swift-XRT refined analysis
- GRB 140102A: MAXI/GSC detection
- GRB 131231A: P60 observations
- Konus-Wind observation of GRB 131229A
- GRB 131229A: CARMA 3mm observations
- GRB 131227A: GROND Upper Limits
- GRB 131227A: Enhanced Swift-XRT position
- GRB 131227A: OT candidate from KAIT Optical observations
- Trigger 581129: Swift-BAT triggered on noise
- GRB 131127B: rejection of optical counterpart candidates
- GRB 131128A; Fermi GBM observation
- GRB 131128A: AROMA-N Optical Observation
- GRB 131128A: T100 observations
- GRB 131128A: MASTER-Net optical observations
- GRB 131127B: Nanshan optical observations
- IPN Triangulation of GRB 131127B
- Fermi407254341: iPTF optical afterglow candidates
- GRB 131122A: Nanshan optical upper limit
- GRB 131108A: 1.23m CAHA optical candidate
- GRB 131028A: Fermi GBM detection
- GRB 131024A: Skynet R-COP optical observations
- GRB 131024A: Swift detection of a burst
- GRB 131014A: Suzaku WAM observation of the prompt emission
- GRB 131002B: Swift detection of a burst
- GRB 130925A: continuing Swift/XRT monitoring
- GRB 130702A: RTT150 optical observations
- GRB 130913A detected in ground analysis of Swift-BAT data
- GRB 130912A: P60 Observations
- GRB 130912A: Swift detection of a short burst
- GRB 130828A: Further Swift XRT observations
- GRB 130831A: ISON-Kislovodsk optical observations
- GRB 130903A: GROND Afterglow Discovery
- GRB 130831A, Swift-BAT refined analysis
- IPN triangulation of GRB 130828A - error box
- IPN triangulation of GRB 130828A
- GRB 130828A: Fermi GBM detection
- GRB 130828A: Fermi-LAT detection of a burst
- GRB 130816A, Swift-BAT refined analysis
- GRB 130816B: Swift detection of a burst
- IPN Triangulation of GRB 130812B (long/soft)
- IPN localization of GRB 130804A
- GRB 130803A: Swift detection of a burst
- GRB 130727A: Swift detection of a burst
- GRB 130725B: Swift trigger time correction
- GRB 130719A: Skynet/PROMPT observations
- Swift Trigger 563980 is GRB 130725A
- GRB 130702A: CARMA 3mm detection
- GRB 130628A: Fermi GBM detection
- GRB 130701A: MITSuME Akeno Optical observation
- GRB 130701A, Swift-BAT refined analysis
- GRB 130701A: optical afterglow from the NOT
- Swift trigger 559221 is likely a false trigger coincident with IGR J17544-2619
- GRB 130627A: Fermi GBM detection
- GRB 130610A: CrAO optical observations
- GRB 130610A: iTelescope T21 optical observations
- GRB 130612A: ISON-NM optical observations
- GRB 130612A: VLT/X-shooter redshift
- GRB 130610A: Swift/UVOT Observations