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"19533 results found.
- GRB050915: XRT position
- GRB 050915: ROTSE-III optical limits
- GRB 050915: Swift detection of a GRB
- GRB050911: Upper limit on X-ray afterglow
- Swift-BAT trigger 155072 ground analysis
- Swift-BAT trigger 155072 is probably not a GRB
- GRB050914: XRT position probably due to cosmic ray
- Swift is in normal operation
- GRB050911: Swift UVOT followup observations
- GRB 050911, optical content of Swift/XRT error box
- GRB050911: Swift-XRT position
- GRB 050911, optical observations
- GRB 050911: Swift-BAT refined analysis
- Later Swift-BAT triggers 154632 and 154633 RETRACTION
- GRB050911: Swift-BAT detection of a long burst
- GRB050908: detection of Swift/UVOT optical counterpart
- RBO GRB 050908 observations
- WIRO observations in I of GRB 050908
- GRB 050906: Possible X-ray Counterpart
- GRB050908: Swift/UVOT Early upper limits
- GRB050908 : Swift-XRT refined analysis
- GRB 050908: Swift-BAT refined analysis
- GRB 050908: Optical observations
- Gemini Spectroscopy of GRB 050908
- GRB 050908 : Swift XRT position
- GRB 050908: KAIT observations
- GRB 050908: P60 Confirmation of Optical Afterglow
- GRB 050908: Swift detection of a burst
- Swift trigger 154073 is not a GRB
- GRB050904: CrAO optical observations
- GRB 050904 BAT refined analysis of complete data set
- GRB 050906: MARGE Optical Limits
- GRB 050906: Swift-BAT refined analysis
- GRB 050906: Swift XRT upper limit
- GRB050906: P60 Observations
- 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: Swift/UVOT observations
- GRB 050904: early Swift XRT analysis results
- GRB 050904: BAT refined analysis of partial data set
- 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
- Swift Trigger #152652 is not a GRB
- GRB050827: Swift/UVOT upper limits
- GRB 050827: Optical Limit
- GRB 050827: XRT possible afterglow detection
- GRB050827: RTT150 optical observations
- GRB 050827: Swift-BAT refined analysis
- GRB050827: Swift-BAT detection of a burst
- 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
- 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
- GRB050822: Swift/UVOT upper limits
- GRB 050820A BAT observations of second, larger episode of emission
- GRB 050822: Swift-BAT refined analysis
- 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
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB050820a BVRcIc field photometry
- GRB050820B XMM-Newton observation
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820B: Refined analysis of the Swift-BAT burst
- GRB050820B: BAT-Swift detection of a bright GRB
- Swift/UVOT photometry of GRB050820
- GRB050820: refined XRT analysis
- GRB 050820: Early RAPTOR detections
- GRB 050820 Swift-BAT refined analysis
- GRB050819: refined XRT analysis
- GRB 050820: Swift detection of a GRB