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"31727 results found.
- GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
- GRB 221009A (Swift J1913.1+1946): Mondy optical observations
- Swift J1913.1+1946 : Pre-discovery limits from ZTF
- GRB 221009A: Fermi GBM observation
- IPN triangulation of extremely bright GRB 221009A
- Swift J1913.1+1946: Optical photometry
- Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
- GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
- GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
- GRB 221009A: Swift detected transient may be GRB
- GRB 221008A: Swift-XRT observations
- GRB 221008A: Tiled Swift observations
- GRB 221006A: Swift-XRT observations
- GRB 221006A: Tiled Swift observations
- GRB 220930A: MITSuME Akeno optical upper limits
- GRB 220912A: Detection by VZLUSAT-2
- GRB220927A: Detection by GRBAlpha
- GRB 220921A: ATCA detection of radio counterpart
- GRB 220930A: AbAO Optical Upper Limit
- Konus-Wind detection of GRB 220930A
- GRB 220930A: AstroSat CZTI detection
- GRB 220930A: Swift-BAT refined analysis
- GRB 220930A: Swift-XRT refined Analysis
- GRB 220930A: LCOGT Optical Upper Limits
- GRB 220930A: Swift/UVOT Upper Limits
- Swift GRB 220930A: Global MASTER-Net observations report
- GRB 220930A: COATLI Upper Limits
- Fermi-LAT gamma-ray observations of IceCube-220928A
- Konus-Wind detection of GRB 220927A
- Fermi GRB 220927A: Global MASTER-Net observations report
- IPN triangulation of GRB 220927A (long)
- GRB 220921A: LCOGT Optical Observations
- GRB 220611A: Host galaxy redshift from VLT/X-shooter
- GRB 220924A: Fermi GBM detection
- Swift Trigger 1125354 (GRB 220926A) is not a GRB
- Swift GRB 220926A: Global MASTER-Net observations report
- Analysis of long GRB 220926B detected by INTEGRAL
- Fermi GRB 220925A: Global MASTER-Net observations report
- GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220921A: ALMA detection
- GRB 220921A: DDOTI Detection of the Afterglow
- Konus-Wind detection of GRB 220921A
- GRB 220921A: Fermi GBM detection
- IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
- GRB 220921A: MeerLICHT afterglow observations
- GRB 220921A: Swift-XRT Observations
- GRB 220921A: MASTER OT inside Fermi-LAT error-box
- GRB 220921A: Tiled Swift observations
- Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
- IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-220907A: No significant detection in HAWC
- GRB 220909A: Fermi GBM observation
- Konus-Wind detection of GRB 220910A
- Fermi GRB 220912A: Global MASTER-Net observations report
- GRB 220910A: Fermi GBM observation
- IPN triangulation of GRB 220910A (bright/long)
- GRB 220912A: AstroSat CZTI detection
- GRB 220831A: DECam optical counterpart follow-up
- GRB 220909A: Swift-XRT observations
- IPN triangulation of GRB 220905A
- GRB 220909A: Swift ToO observations
- GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
- GRB 220831A: Gemini-South Infrared Observations
- GRB 220910A: AstroSat CZTI detection
- GRB 220907A: Swift-BAT refined analysis
- IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
- GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
- IPN triangulation of GRB 220903A (long)
- GRB 220907A: Fermi GBM observation
- GRB 220907A: Nanshan/NEXT optical upper limits
- GRB 220907A: Swift/UVOT Upper Limits
- GRB 220907A: Swift-XRT refined Analysis
- GRB 220831A: ATCA 5/9 GHz radio observations
- Fermi-LAT Gamma-ray Observations of IceCube-220907A
- GRB 220907A: Swift-XRT position
- GRB 220907A: Swift detection of a burst
- GRB 220831A: Swift-UVOT Upper Limits
- Fermi GRB 220905A: Global MASTER-Net observations report
- Introducing Self-Service Configuration of GCN Notices over Email for Transient Alerts
- GRB 220831A: DECam detection of a possible optical counterpart
- Fermi GRB 220902A: Global MASTER-Net observations report
- GRB 220831A, VLT/HAWK-I near-infrared observations
- GRB 220831A: Fermi GBM observation
- GRB 220831A: Swift-XRT observations
- GRB 220831A: Swift ToO observations
- GRB 220831A: Swift/BAT-GUANO localization of a short burst
- IceCube-220822A: No significant detection in HAWC
- Konus-Wind detection of GRB 220826A
- IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
- GRB 220826A: Swift-BAT refined analysis
- GRB 220826A: Fermi GBM observation
- GRB 220826A: Swift-XRT refined Analysis
- GRB 220825A: Fermi GBM observation
- GRB 220826A: Lesedi optical afterglow detection
- GRB 220826A: Swift/UVOT Detection
- GRB 220826A: iTelescope optical afterglow observations
- Swift GRB 220826A: Global MASTER-Net observations report
- IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
- GRB 220823A: Fermi GBM detection
- Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154