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"11503 results found.
- Konus-Wind and Konus-RF observations of GRB 090618
- GRB 090621B: Swift-XRT refined analysis
- GRB 090621B: RTT150 optical observations
- GRB 090621B: Optical Observations
- GRB 090621A: Swift-BAT refined analysis
- GRB 090618 15GHz radio detection
- GRB090618: Swift-XRT team refined analysis
- GRB 090618: Lick/KAST Spectroscopy
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- Konus-RF observation of SGR burst 090605A
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- GRB 090607: XRT Team Refined Analysis
- GRB 090607: Swift detection of a burst
- GRB 090528B: Suzaku WAM observation of the prompt emission
- GRB 090531B: ROTSE-III Optical Limits
- GRB 090530: break in light curve
- GRB090530: Swift XRT refined analysis
- Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
- GRB 090530: Swift detection of a burst with an optical counterpart
- GRB 090529: optical observations
- GRB 090529: Xinglong TNT optical observation
- GRB 090529: Swift detection of a burst
- GRB 090520D: Fermi GBM detection
- GRB 090520C: Fermi GBM detection
- GRB 090520B: Fermi GBM detection
- GRB 090522 : Fermi GBM detection
- GRB 090518 - NOT upper limit
- GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090516C: Fermi GBM detection
- GRB 090520 Swift-BAT detection of a burst in ground analysis
- GRB 090516: Fermi GBM observation
- GRB 090519: Swift detection of a burst
- GRB 090518: Swift-XRT refined analysis
- GRB 090518: Swift detection of a burst
- GRB 090516: Swift-BAT refined analysis
- GRB 090516: Swift XRT refined analysis
- GRB 090516: Swift detection of a burst
- GRB 090515: Swift-XRT refined analysis
- GRB 090515: WIYN NIR Upper Limit
- GRB 090515: ROTSE-III Optical Limits
- GRB 090515: Swift detection of a short burst
- GRB 090510: Fermi-LAT follow-up analysis
- Konus-Wind observation of GRB 090510
- GRB 090510: Swift XRT refined analysis
- Fermi LAT detection of GRB 090510
- GRB 090510: Swift detection of a short hard burst
- GRB 090418A: optical observation
- GRB 090509: Swift detection of a burst
- GRB 090423: optical limit
- GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
- GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
- GRB 090427: GROND observations
- GRB 090424: YNAO-GMG observations
- GRB 090429A: Swift-XRT refined analysis
- GRB 090429B: Swift XRT refined analysis
- Konus-Wind observation of very bright GRB 090427
- GRB 090426: GAO 150cm telescope Optical Observation
- GRB 090426: YNAO-GMG observations
- GRB 090429B: GROND Observations
- GRB 090429B: Super-LOTIS early observations
- GRB 090429B: Swift detection of a burst
- IPN triangulation of very bright GRB 090427
- GRB 090424: Continued R-band monitoring
- GRB 090426: Okayama MITSuME optical observation
- GRB 090426: Swift detection of a burst with an optical counterpart
- GRB 090424: THO optical observations
- GRB 090424 optical observations
- GRB 090424: Swift-XRT refined analysis
- GRB 090424: Fermi GBM Observation
- GRB 090423 limiting magnitudes
- GRB 090423: UKIRT K-band observations
- GRB 090423: P60 Observations
- GRB 090423: Swift detection of a burst
- GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090418B: RTT150 optical observations
- GRB 090418A: RTT150 optical observations
- GRB 090418B: GROND observations
- Konus-Wind observation of GRB 090418B
- GRB 090418A: ROTSE-III Refined Analysis
- GRB 090418: Swift detection of a burst with optical afterglow
- GRB 090411B: Suzaku WAM observation of the prompt emission
- GRB 090411A: Suzaku WAM observation of the prompt emission
- GRB 090417B: MITSuME Okayama optical upper limits
- GRB 090417B: Swift detection of a burst
- GRB 090411A: Fermi GBM detection
- Konus-Wind and Konus-RF observations of GRB 090408b
- GRB 090409: Fermi GBM detection
- GRB 090407: GROND upper limits
- GRB 090407: Swift-XRT refined analysis
- Konus-Wind and Konus-RF observations of GRB 090406
- GRB 090407: ROTSE-III Optical Limits
- GRB 090407: Swift detection of a burst
- GRB 090404: NOT observations
- GRB 090404: Swift-XRT Team refined analysis
- Konus-Wind observation of GRB 090401B
- GRB 090328: Fermi-LAT refined analysis
- GRB 090331: Fermi GBM detection
- Konus-Wind observation of GRB 090401A
- Swift/UVOT detection of GRB090401B
- GRB 090401B: Swift detection of a burst