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"19808 results found.
- GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
- GRB 090427: GROND observations
- GRB 090429A: ROVOR magnitude limit
- GRB 090424, SMARTS optical/IR afterglow monitoring
- GRB 090429B: Swift/UVOT Upper Limits
- GRB 090429A: Swift/UVOT Upper Limits
- GRB 090429B: Gemini-N further nIR observations
- GRB 090429A: GROND upper limits
- GRB 090429A: Enhanced Swift-XRT position
- Konus-Wind observation of very bright GRB 090427
- GRB 090418A BVRcIc field calibration
- GRB 090429B: RIMOTS optical upper limits
- GRB 090429B: Swift-BAT refined analysis
- GRB 090429B: Enhanced Swift-XRT position
- GRB090429B: Gemini-N infrared IR candidate
- GRB 090429B: VLT upper limits
- GRB 090429B: GROND Observations
- GRB 090429B: Super-LOTIS early observations
- GRB 090429B: Swift detection of a burst
- GRB 090429: Swift detection of a burst
- GRB 090424 : Multiband Optical observation from Nainital
- IPN triangulation of very bright GRB 090427
- GRB 090423: CARMA mm observations
- GRB 090426: GROND Observations of the Optical/NIR Afterglow
- GRB 090423: GROND second epoch imaging and refined SED
- Detection of bright radio afterglow of GRB 090424 with the VLA
- GRB 090426: Enhanced Swift-XRT position
- GRB090426: Observation for Optical counterpart from MIRO
- GRB 090426, RIMOTS optical upper limits
- GRB 090426: Swift detection of a burst with an optical counterpart
- GRB 090424: MASTER-Net prompt optical limit
- VLA radio observation of high-z GRB 090423
- GRB 090424: THO optical observations
- GRB 090424: GROND Observations of the Optical/NIR Afterglow
- GRB 090423: Y-band field calibration update/correction
- GRB 090424 : TAOS optical detection
- GRB 090424: Liverpool Telescope observations
- GRB 090424: Optical observations from 1.23m CAHA
- GRB 090423: energetic, luminosity and jet break
- GRB 090424: MASTER-Net prompt optical observations
- GRB 090424: Enhanced Swift-XRT position
- GRB 090424: Swift detection of a burst with an optical counterpart
- GRB090423: Y-band field calibration
- GRB 090423 limiting magnitudes
- GRB 090423: Near infrared observation at Okayama Observatory
- GRB 090423: Deep z-band upper limit and confirmation of photo-z
- GRB 090423: GROND detection and preliminary photo-z
- GRB 090423: NOT z-band limit
- GRB090418A Rc-band photometry
- GRB 090423: NIR photometry and evidence for spectral break
- GRB090423, RIMOTS optical upper limits
- GRB 090423: Enhanced Swift-XRT position
- GRB 090423: Swift-BAT refined analysis
- GRB 090422: Swift/UVOT Upper Limits
- GRB 090423: UKIRT K-band observations
- GRB 090423: P60 Observations
- GRB 090418A: R and I band observation
- GRB 090423: Swift detection of a burst
- GRB 090422: Enhanced Swift-XRT position
- GRB 090418B: RTT150 optical observations
- GRB 080410: GAO 150cm telescope Optical Observation
- GRB 080408A: GAO 150cm telescope Optical Observation
- GRB 090422: Swift detection of a burst
- GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
- GRB 090418B: GRAS002 observatios
- GRB 090418A: optical observations
- GRB 090418B: GROND observations
- GRB 090419: Swift/UVOT Observations
- GRB 090418B: Faulkes Telescope North observations
- GRB 090418A: Swift/UVOT Observations
- GRB 090417B: Swift/UVOT Upper Limits
- GRB 090419: Swift-XRT refined analysis
- GRB 090419: GROND detection of afterglow candidate
- GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
- VLA radio detection of GRB 090418
- VLA radio upper limit on GRB 090417B
- GRB 090419: Enhanced Swift-XRT position
- GRB 090418: Swift XRT refined analysis
- GRB 090419: Swift detection of a burst
- VLA observations of short burst GRB 090417A
- GRB 090418B: Detection of a bright burst from Swift-BAT slew data
- GRB 090417B: Gemini imaging
- GRB 090418: Enhanced Swift-XRT position
- GRB 090418: Swift detection of a burst with optical afterglow
- GRB 090417B: Subaru NIR Observations
- GRB 090417B: MITSuME Okayama optical upper limits
- GRB 090417B: optical observations
- GRB090417B: optical observations
- GRB 090417B: Swift detection of a burst
- GRB 090411A: Fermi GBM detection
- GRB 090410: GROND upper limits
- GRB 090410: MITSuME optical upper limits
- GRB 090408b: IPN Triangulation
- GRB 090328b: IPN Triangulation
- Konus-Wind and Konus-RF observations of GRB 090408b
- GRB 090409: Fermi GBM detection
- GRB090408, RIMOTS optical upper limits
- Swift-BAT trigger 348781: almost certainly not a burst
- GRB 090408B: MASTER II-Kourovka optical observations
- GRB 090407: GROND upper limits