GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"- GRB 050908: KAIT observations
- GRB 050908: P60 Confirmation of Optical Afterglow
- GRB 050908: Optical Observations
- GRB 050908: Swift detection of a burst
- Swift trigger 154073 is not a GRB
- GRB 050906: Optical observations at the Very Large Telescope
- GRB050904: CrAO optical observations
- GRB 050904 BAT refined analysis of complete data set
- GRB 050904: Subaru Optical Spectroscopy
- GRB 050906: MARGE Optical Limits
- GRB 050906: Swift-BAT refined analysis
- GRB 050906: Swift XRT upper limit
- GRB 050906: Radio Observations
- GRB 050904: Keck I-band Imaging
- GRB050906: P60 Observations
- GRB 050904: more VLT NIR observations
- GRB 050904: BOOTES early R-band observation
- GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
- GRB 050906: Bright galaxy in BAT error box
- GRB 050906: Swift/BAT Detection of a possible burst
- GRB 050904: More SOAR
- GRB 050904: photometric redshift
- GRB 050904: Swift/UVOT observations
- GRB 050904: Afterglow Astrometry
- GRB 050904: NIR object inside the XRT error box
- GRB 050904: early Swift XRT analysis results
- GRB 050904: SOAR YJ and PROMPT Ic Observations
- GRB 050904: BAT refined analysis of partial data set
- GRB 050904: TAROT optical measurements
- GRB050904: Optical Observations
- GRB 050904: Environmental Constraints
- GRB 050904: Possible High-Redshift GRB
- GRB 050904: SOAR/PROMPT Observations
- GRB050904: P60 Observations
- GRB 050904: TAROT optical limits
- GRB050904: Swift-BAT detection of a probable burst
- Swift-BAT triggers 153461-153465 are not GRBs
- Retraction of Swift-BAT trigger #153355
- GRB 050824: MDM Observations
- GRB 050827: Swift XRT preliminary analysis results
- IBAS Alerts 2641 and 2642: not a real GRB
- Swift Trigger #152652 is not a GRB
- GRB 050827 : OSN 1.5m optical observations
- GRB 050827: P200 NIR Observations
- GRB050827: Swift/UVOT upper limits
- GRB 050827: Optical Limit
- GRB 050827: XRT possible afterglow detection
- GRB 050826 : Lulin R band observation
- GRB050824: Maidanak optical limits
- GRB050820A: RTT150 optical observations
- GRB050827: RTT150 optical observations
- GRB 050827: Swift-BAT refined analysis
- GRB050827: Swift-BAT detection of a burst
- Subaru Observations of GRB050724
- GRB 050826: Optical Candidate
- GRB050824, HETE-2 Observation
- GRB 050826: Swift XRT preliminary analysis results
- GRB 050826: BAT refined analysis
- GRB050826: Swift/UVOT early upper limits
- GRB050824: First 2 hours of power low optical decay?
- GRB 050826: Swift XRT position
- GRB050826: Swift-BAT detection of a long burst
- GRB050824: MASTER final analysis of the OT observations
- Possible GRB050825:MASTER optical observations
- Swift-BAT trigger 152038 is definitely not a GRB
- GRB050824: CORRECTION to UVOT observing times
- Swift-BAT trigger 152038 is probably not a GRB
- GRB050824: Swift/UVOT detection of fading afterglow
- GRB050824: decay of the XRT light curve and updated X-ray spectrum
- GRB050824, I-band imaging
- GRB050824: Radio Observations
- GRB 050824: Spectroscopic redshift from the VLT
- GRB 050822: refined XRT analysis
- GRB 050824: XRT refined analysis and possible afterglow detection
- GRB 050824: BAT refined analysis of a soft weak burst
- GRB050824: MASTER:OT decay
- GRB050824: MASTER observation OT
- GRB050805a: MASTER optical candidat
- GRB 050824: ROTSE-III Optical Limits
- GRB050824: Swift-BAT detection of a burst
- GRB 050824 optical candidate
- GRB050820A: RTT150 optical observations
- GRB050820a: PROMPT RcIc Observations
- GRB050815: Maidanak optical observation
- XRF050509c: Radio upper limits from GMRT
- VLT/UVES spectroscopy of GRB050820
- GRB050822: Swift/UVOT upper limits
- GRB 050820A BAT observations of second, larger episode of emission
- GRB050813: Maidanak I-band observations
- GRB 050822: Swift-BAT refined analysis
- GRB050525, GRB050607, GRB050802 BVRcIc field photometry
- GRB050820B at FRAM
- GRB050820A: RTT150 optical observations
- GRB 050820a - corrections to GCN 3846
- Swift/UVOT UV Photometry of GRB 050820B
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB 050822: Swift detection of a long burst
- Correction to Eiso calculation in GCN 3835 on GRB 050820A
- GRB050820A: Radio Observation
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)