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"4903 results found.
- 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
- GRB 120923A: GROND Upper limits
- GRB 120923A: Gemini afterglow detection, high-z candidate
- Konus-Wind observation of GRB 120919A
- IPN Triangulation of long GRB 120919A
- GRB 120919A: Fermi GBM detection
- Swift Trigger 533836 is a new Galactic transient
- GRB 120911A: Faulkes Telescope North observations
- GRB 120907A: Fermi GBM detection
- GRB 120907A: Swift detection of a burst with optical counterpart
- GRB 120817A: Swift detection of a burst
- GRB 120816A: BOOTES-2 observations
- GRB 120816A: ROTSE-III Optical Limits
- Konus-Wind observation of GRB 120811B
- Swift Trigger 530581: GRB 120811A or a galactic transient
- GRB 120803A: optical upper limit
- GRB 120804A: Konus-Wind and Swift/BAT joint spectral analysis
- Fermi/GBM detection of an SGR-like burst
- GRB 120804A: Swift-BAT refined analysis
- GRB 120803A: Swift detection of a possible burst
- IPN Triangulation of GRB 120728B (long/intense)
- Swift Trigger 528925 is probably a noise fluctuation
- GRB 120724A: optical observation in Maidanak observatory
- GRB 120724A: JCMT SCUBA-2 sub-mm observation
- GRB 120724A: Gemini-N tentative redshift
- GRB 120724A: FTN optical afterglow candidate
- Konus-Wind observation of GRB 120707A
- GRB 120624B: Discussion of Fermi and Swift measurements and future Swift observations
- GRB 120624A: Fermi GBM observation
- GRB 120624B: Fermi-LAT Detection
- Konus-Wind observation of GRB 120624A
- GRB 120624B: Fermi GBM detection
- IPN Triangulation of GRB 120624A (short/intense)
- IPN Triangulation of GRB 120602A (long/very bright)
- GRB 120519A: Suzaku WAM observation of the prompt emission
- GRB 120512A: Suzaku WAM observation of the prompt emission
- IPN Triangulation of GRB 120519A (short/hard)
- Fermi/GBM detection of a burst from the magnetar 1E 2259+5
- GRB 120422A: CARMA 3mm observations
- Swift detection of 4U 1630-47
- GRB 120424A: MAXI/GSC detection of a burst
- SGR1806-20, Swift-BAT refined analysis (Trigger 519868)
- Trigger 519868: Swift detection of SGR1806-20
- GRB 120404A: MASTER OT observations
- GRB 120404A: MASTER early OT limit
- GRB 120402B: Fermi GBM detection
- GRB 120401A: Swift detection of a burst
- GRB120327A - ATCA radio afterglow detection at 34GHz