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"30471 results found.
- Afterglow limits of GRB 221006A from OHP
- GRB221009A: optical afterglow measurements from Konkoly Observatory
- Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
- GRB 221009A: COATLI Continued Monitoring of the Afterglow
- INTEGRAL detection of a burst from SGR J1935+2154
- GRB 221009A: NuSTAR Detection
- GRB 221009A: NICER follow-up observations
- GRB 221009A: LCOGT Optical Afterglow Detection
- GRB 221009A: COATLI Detection of the Afterglow
- GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
- GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
- GRB 221009A: Detection by GRBAlpha
- GRB 221009A: Sintez-Newton/CrAO optical observations
- GRB 221009A: Upper limits from HAWC 8 hours after trigger
- GRB 221006A: Swift ToO observations
- Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
- GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
- GRB 221009A: BlackGEM optical observations
- LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
- GRB 221009A: NOEMA mm detection
- GRB 221006A: CALET Gamma-Ray Burst Monitor detection
- GRB 221009A: Continued Swift/XRT observations
- GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
- GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
- Konus-Wind detection of GRB 221009A
- GRB 221009A: Lulin SLT-40cm optical observations
- Swift J1913.1+1946: New Photometry
- GRB 221009A: Upper limits from a neutrino search with IceCube
- GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
- GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
- GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
- GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
- GRB 221009A: Multi-color detection of the optical
- GRB 221009A: Fermi-LAT refined analysis
- GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
- GRB 221009: Swift/UVOT Detection
- GRB221009A/Swift J1913.1+1946: ATA follow-up observations
- GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
- GRB 221009A: REM optical and NIR detection of the afterglow
- GRB 221009A: Swift-XRT refined Analysis
- GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
- Swift J1913.1+1946: Early Optical Photometry
- GRB 221009A: Redshift from X-shooter/VLT
- GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
- 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)