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"14831 results found.
- GRB 240123A: Glowbug gamma-ray detection
- GRB 240125A (short): Glowbug gamma-ray detection
- GRB 240123B: Swift/BAT-GUANO detection of a long burst
- GRB 240123A: GRBAlpha detection
- GRB 240122B: CALET Gamma-Ray Burst Monitor detection
- GRB 240123A : MITSuME Akeno optical afterglow candidate detection
- GRB 240122A: Swift/UVOT Upper Limits
- GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
- Fermi GBM Sub-Threshold Detection of GRB 240123A
- GRB 240123B: Fermi GBM Final Real-time Localization
- GRB 240122B: Glowbug gamma-ray detection
- IceCube-240123A - IceCube observation of a high-energy neutrino candidate track-like event
- Konus-Wind detection of GRB 240112A
- GRB 240123A: Swift detection of a burst with a possible optical counterpart
- GRB 240122A: Swift-XRT afterglow detection
- GRB 240122A: VLT/X-shooter redshift confirmation
- GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
- Konus-Wind detection of GRB 240119A (short/hard)
- GRB 240122A: MAXI/GSC detection
- IPN triangulation of GRB 240119A (short)
- GRB 240119A: GECAM detection of a short burst
- GRB 240118C: GECAM-B detection of a long burst
- GRB 240119A: AstroSat CZTI detection of a short burst
- GRB 240118A: Swift-XRT afterglow detection
- IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
- GRB 240119A: Fermi GBM Final Localization
- GRB 240117A: CALET Gamma-Ray Burst Monitor detection
- GRB 240118C: Swift/BAT-GUANO detection of a burst
- GRB 240118A: GRBAlpha detection
- GRB 240118D: AstroSat CZTI detection
- GRB 240117A: AstroSat CZTI detection
- GRB 240117A: Glowbug gamma-ray detection
- GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- Konus-Wind detection of GRB 240118A
- GRB 240118A: NuSTAR Detection of a Long GRB
- GRB 240118B: Fermi GBM Final Real-time Localization
- GRB 240118A: Fermi-LAT detection
- GRID detection of GRB 231230A
- GRB 240118A: Fermi GBM Final Real-time Localization
- GRB 240115A: Swift/BAT-GUANO detection of a short burst
- IPN triangulation of GRB 240112A (long)
- GRB 240115B: AstroSat CZTI detection
- GRB 240115B: Fermi GBM Detection
- IceCube-240105A: ZTF optical observation of blazar PKS 0446+11
- GRB 240112D: Glowbug gamma-ray detection
- GRB 240112C: Glowbug gamma-ray detection
- GRB 240112C: VZLUSAT-2 detection
- GRB 240107A: VZLUSAT-2 detection
- GRB 240115B: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240112C
- GRB 240115A: Fermi GBM Final Real-time Localization
- GRB 240112C: GRBAlpha detection
- GRB 240114A: MAXI/GSC detection
- GRB 240112C: Swift/UVOT Detection
- GRB 240112C: Fermi GBM Detection
- GRB 240112E: Fermi GBM Final Localization
- GRB 240112D: Fermi GBM Final Real-time Localization
- GRB 240112C: Swift detection of a burst with an optical counterpart
- GRB 240112B: Fermi GBM Final Real-time Localization
- GRB 240112A: GECAM detection of a burst
- GRB 240110A: AstroSat CZTI detection
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
- GRB 240108A: Glowbug gamma-ray detection
- GRB 240106B: Glowbug gamma-ray detection
- GRB 240106A: Glowbug gamma-ray detection
- GRB 240109B: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240101C
- GRB 231215A: radio detection with the VLA
- GRB 230812B: further radio observations with the VLA
- GRB 240107A: AstroSat CZTI detection
- GRB 240109A: Swift detection of a short burst
- IceCube-240105A: JCMT SCUBA2 Detection of Two Bright Submillimeter Sources
- GRB 240106A: GRBAlpha detection
- GRB 240107A: MAXI/GSC detection
- GRB 240106B: Fermi GBM Final Real-time Localization
- GRB 240106A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 240101C (short)
- GRB 240101A: 1.3m DFOT optical observations
- IceCube-240105A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 240102A: 1.3m DFOT optical upper limit
- GRB 240101B: 1.3m DFOT optical upper limit
- GRB 240101C: Swift/BAT-GUANO detection of a short burst
- GRB 240102C: AstroSat CZTI detection
- GRB 240101C: AstroSat CZTI detection
- GRB240102A: BOOTES-6/DPRT optical upper limit
- GRB 240102B: Fermi GBM Final Real-time Localization
- GRB 240102A: Swift detection of a burst
- GRB 240101C: GRBAlpha detection
- GRB 240101C: Fermi GBM Final Localization
- GRB 240101B: Swift detection of a burst
- GRB 240101A: Swift detection of a burst
- GRB 231230A: Swift detection of a burst
- GRB 231230A: Fermi GBM Final Real-time Localization
- GRB 231210B: BOOTES-7 optical upper limit
- IPN triangulation of GRB 231224A (short)
- GRB 231224A: Fermi GBM Final Real-time Localization
- GRB 231222B: GRBAlpha detection
- GRB 231222B: Swift-XRT afterglow detection
- GRB 231222B: Fermi GBM Detection
- GRB 231222B: Fermi-LAT detection