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"26040 results found.
- GRB 220907A: Swift detection of a burst
- Swift GRB220907.59: Global MASTER-Net observations report
- GRB 220831A: Swift-UVOT Upper Limits
- GRB 220831A: DECam detection of a possible optical counterpart
- 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
- Konus-Wind detection of GRB 220826A
- 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
- GRB 220826A: Enhanced Swift-XRT position
- GRB 220826A: Swift detection of a burst with an optical counterpart
- GRB 220825A: Swift/BAT-GUANO detection
- GRB 220823A: Fermi GBM detection
- GRB 220823A: Swift/BAT-GUANO detection of a short burst
- Konus-Wind detection of GRB 220813A
- GRB 220813A: VLT optical observations and possible host galaxy
- GRB 220813A: Swift/UVOT Detection
- GRB 220810A: Further Swift-XRT observations
- GRB 220813A: Swift-XRT refined Analysis
- Swift GRB 220813A: Global MASTER-Net observations report
- GRB 220813A: Enhanced Swift-XRT position
- GRB 220813A: Swift detection of a burst with an optical counterpart
- GRB 220810A: Swift-XRT observations
- GRB 220810A: Swift ToO observations
- GRB 220810A: MeerLICHT detection of two afterglow candidates
- GRB 220806A: Swift-BAT refined analysis
- GRB 220806A: Swift detection of a burst
- Swift GRB220806.76: Global MASTER-Net observations report
- Konus-Wind detection of GRB 220730A (short)
- GRB 220730A: Swift-BAT refined analysis
- GRB 220730A: Fermi GBM detection
- GRB 220730A: Swift-XRT afterglow detection
- GRB 220730A: Swift/UVOT Upper Limits
- GRB 220730A: Swift-XRT observations
- Swift GRB 220730A: Global MASTER-Net observations report
- GRB 220730A: Swift detection of a short hard burst
- GRB 220715B: VIRT Optical Upper Limit
- GRB 220711B: CALET Gamma-Ray Burst Monitor detection
- GRB 220715B: Swift-BAT refined analysis
- GRB220714B: UVOT detections
- GRB 220715B: Fermi GBM detection
- GRB 220715B: Swift-XRT refined Analysis
- GRB 220715B: Swift/UVOT Upper Limits
- GRB 220715B: Enhanced Swift-XRT position
- GRB 220715B: BOOTES-network optical upper limits
- Swift GRB 220715B: Global MASTER-Net observations report
- GRB 220715B: Prompt enhanced Swift-XRT position
- GRB 220715B: Swift detection of a burst
- GRB 220714B: Swift-BAT refined analysis
- GRB 220714B: Fermi GBM observation
- GRB 220714B: LCO Optical Observations
- GRB 220714B: Swift-XRT refined Analysis
- Swift/BAT Trigger 1116172 (=GRB 220714A) is not a real astrophysical event
- GRB 220714B: UVOT afterglow discovery
- GRB 220714B: Enhanced Swift-XRT position
- GRB 220714B: Swift detection of a burst
- GRB 220714A: Possible Swift detection of a burst
- GRB 220710A: Swift/UVOT Upper Limits
- GRB 220711C: Fermi GBM Observation
- GRB 220711B: 10.4 m GTC(+EMIR) observations
- GRB 220711B: 10.4 m GTC(+EMIR) observations
- GRB 220710A: Swift-XRT afterglow detection
- GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
- GRB 220711B: GIT optical upper limits
- GRB 220712B: NOT optical afterglow confirmation
- GRB 220710A: Swift ToO observations
- GRB 220710A: Swift/BAT-GUANO arcminute localization
- GRB 220711B: Swift-BAT refined analysis
- IPN triangulation of GRB 220711C (short)
- GRB 220711B: Swift-XRT refined Analysis
- GRB 220711B: Swift/UVOT Upper Limits
- GRB 220711B: Enhanced Swift-XRT position
- GRB 220711B: Fermi GBM Detection
- GRB 220711B: NOT optical observations
- GRB 220711B: LCO Optical Upper Limits
- GRB 220711B: Swift detection of a burst
- GRB 220708B: GIT optical upper limits
- GRB 220708A: Swift-BAT refined analysis
- GRB 220708B: T193-OHP optical upper limit
- Konus-Wind detection of GRB 220708B
- GRB 220708B: CALET Gamma-Ray Burst Monitor detection
- GRB 220708B: Nanshan/NEXT optical upper limits
- GRB 220708A: Swift/UVOT Upper Limits
- GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
- GRB 220708A: Swift-XRT refined Analysis
- GRB 220706A: Swift/UVOT Upper Limits
- GRB 220708B: Swift-XRT afterglow detection
- GRB 220708A: BOOTES-5/JGT early optical upper limit
- GRB 220706A: Swift-BAT refined analysis
- GRB 220708A: Enhanced Swift-XRT position