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"5050 results found.
- GRB 130505A: Swift detection of a burst with optical afterglow
- GRB 130504A: MITSuME Okayama upper limits
- GRB 130502B: Suzaku WAM observation of the prompt emission
- Swift-XRT X-ray afterglow candidate for GRB 130504A (BAT trigger 555096)
- GRB 130502B: Fermi GBM detection of a burst
- GRB 130427B: MITSuME Ishigakijima upper limits
- GRB 130427A: Nishi-Harima NIR Observations
- GRB 130427A: Swift-XRT refined Analysis
- GRB 130427B: Swift-XRT refined Analysis
- IPN Triangulation of GRB 130425A
- GRB 130420B: Swift-XRT refined Analysis
- GRB 130420A: Swift-XRT refined Analysis
- GRB 130420B: MASTER-Net optical observations
- GRB 130418A: SMARTS optical/IR afterglow observations
- GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
- Trigger 553930: Swift detection of a possible flare from HR 5110
- GRB 130408A: SMARTS optical/IR afterglow observations
- GRB 130408A: Swift-XRT refined Analysis
- GRB 130327B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 130320B
- IPN Triangulation of GRB 130320B (very long/bright)
- Swift/XRT observation of GRB 130327B
- GRB 130310A: RATIR Observations
- Konus-Wind observation of GRB 130327B
- GRB 130327B: Fermi-LAT detection of a burst
- GRB 130327B: Fermi GBM detection
- GRB 130327B: gamma-ray detection by AGILE
- GRB 130327A: Swift-XRT refined Analysis
- GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
- GRB 130219A: Suzaku WAM observation of the prompt emission
- Trigger 549841: Swift detection of SGR1806-20
- IPN Triangulation of GRB 130219A
- GRB 130216A: Swift detection of a burst
- GRB 130211A: Swift-XRT refined Analysis
- GRB 130131A: optical observation in Mondy observatory
- GRB 130131B: Swift-XRT refined Analysis
- GRB 130131A: VLA 5.8 Ghz Detection
- GRB 130131A: Swift-XRT refined Analysis
- GRB 130131A - UKIRT afterglow candidate
- Swift/BAT trigger 547142 is new source Swift J1753.7-2544
- Swift Trigger 547142: MAXI/GSC upper limit
- GRB 130122A: Swift-XRT refined Analysis
- Short GRB 121226A: TNG observation of the host galaxy
- GRB 130102A: Swift-XRT refined Analysis
- GRB 121226A: 5.8 GHz VLA observations
- GRB 121229A: Swift-XRT refined Analysis
- GRB 121226A: 10.4m GTC optical observations
- GRB 121226A: Swift-XRT refined Analysis
- GRB 121226A, Swift-BAT refined analysis
- GRB 121226A: BOOTES-4/MET optical observations
- GRB 121226A: Swift detection of a burst
- GRB 121225A: MAXI/GSC detection
- GRB 121217A: Swift-XRT refined Analysis
- GRB 121123A: NIKA (New IRAM KID Arrays) millimetre observations at the 30-m Pico Veleta telescope
- GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
- GRB 121212A: Swift-XRT refined Analysis
- GRB 121211A: Swift-XRT refined Analysis
- GRB 121209A: Swift-XRT refined Analysis
- GRB 121209A: GROND optical afterglow candidate
- GRB 121202A: Swift-XRT refined Analysis
- GRB 121201A: Swift-XRT refined Analysis
- IPN Triangulation of GRB 121127A (short/hard)
- GRB 121128A: Swift-XRT refined Analysis
- GRB 121125A: Swift-XRT refined Analysis
- GRB 121125A: Fermi GBM Observation
- GRB 121125A: LOAO Observation
- GRB 121123A: GROND observations
- GRB 121123A: Swift-XRT refined Analysis
- GRB 121117A: Swift-XRT refined Analysis
- GRB 121108A: Swift-XRT refined Analysis
- GRB 121102A: Swift-XRT refined Analysis
- GRB 121029A Suzaku WAM observation of the prompt emission
- Swift Quick-look and HEASARC are back online
- GRB 121024A: LOAO RIzY Observation
- GRB 121024A: SMARTS optical/IR afterglow observations
- GRB 121029A: Fermi GBM detection
- Swift Quick-look and HEASARC will be offline for 24 hours this weekend
- GRB 121024A: optical observations
- GRB 121024A: GMG optical observation
- GRB 121024A: MITSuME Ishigakijima upper limits
- GRB 121024A: MITSuME Okayama Optical upper limits
- GRB 121024A: PAIRITEL NIR Detection
- GRB 121024A: Swift-XRT refined Analysis
- GRB 121017A: Swift-XRT refined Analysis
- GRB 121011B: Suzaku WAM observation of the prompt emission
- GRB 121012A: Fermi GBM detection
- GRB 121011A: Swift-XRT refined Analysis
- GRB 121011A: MASTER-Net bell light curve
- GRB121011A : Xinglong TNT optical observation
- Trigger 535747: Swift detection of an outburst from SGR1806-20
- GRB 121001A: GROND Afterglow Confirmation
- GRB 121001A: Swift-XRT refined Analysis
- GRB 121001A: Enhanced Swift-XRT Position
- Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
- Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
- GRB 121001A: possible optical counterpart
- Swift Trigger 535026: ROTSE-III Optical Limits
- GRB 120927A: Swift-XRT refined Analysis
- GRB 120927A: Enhanced Swift-XRT position
- GRB 120927A: Swift detection of a burst