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"21458 results found.
- GRB 060219: Partial refined analysis of the Swift-BAT burst
- GRB 060219: Swift-XRT position typo correction
- GRB 060219: Swift-XRT position
- GRB 060218: optical/nIR observations at La Palma
- GRB 060219: Swift-BAT detection of a weak burst
- Oddball GRB 060218, transient or GRB?
- GRB060218: Swift/XRT Team preliminary analysis of the possible burst
- Brightening of the Optical Counterpart of the Possible GRB 060218
- GRB 060218: MDM Observations
- GRB 060218: Pre-burst detection of a possible host galaxy
- GRB 060218A: ROTSE-III Possible Optical Flare
- GRB060218: Swift/XRT refined position of a possible burst
- Preliminary refined analysis of the Swift-BAT trigger 191157
- Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
- GRB 060211B: Swift/UVOT Upper Limits
- GRB 060218: Swift XRT Position
- GRB 060218: Swift-BAT detection of a possible burst
- GRB 060213: optical afterglow not confirmed
- Swift UVOT observations of GRB060213
- GRB 060213: optical afterglow candidate
- GRB060213: Swift XRT observations and possible afterglow candidate
- GRB 060211b: WIRO NIR Observations
- GRB060206: Swift XRT observations of an unbroken powerlaw decay
- GRB 060213: IPN localization
- GRB 060211a: WIRO NIR Observations
- GRB060211B: REM optical and NIR observations
- GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
- GRB 060211A: Further refined analysis of the Swift burst
- GRB060121: optical observations
- GRB060105: optical observations
- GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
- GRB 060211b: P60 Observations
- GRB 060211A: Partial refined analysis on the Swift-BAT burst
- GRB 050826: Optical Afterglow and Host Galaxy
- GRB 060210: Further refined analysis of the Swift-BAT burst
- GRB 060211B: Swift/BAT refined analysis
- GRB060210: Swift/UVOT Upper Limits
- GRB 060211B: Swift-XRT Team refined analysis
- GRB060211b: optical observation
- GRB060211B: Swift/XRT position
- GRB 060210: Optical Observations
- GRB 060211A: Swift XRT Team Refined Analysis
- GRB 060211B: Swift-BAT detection of a burst
- GRB060211: Faulkes North observation
- GRB 060211: Swift detection of a long burst
- GRB 060210: Refined analysis of the Swift-BAT burst
- GRB060210: Swift XRT Refined Analysis
- GRB060210: Early Optical Observations
- GRB060210:Faulkes Telescope North Afterglow Confirmation
- GRB 060210: candidate afterglow
- GRB 060210: Swift detection of a burst
- GRB060210: Optical afterglow
- GRB 060206: Swift/UVOT Observations
- Swift-BAT trigger 180931 is not a GRB
- GRB060209: RTT150 optical observations
- GRB 060209 : TAROT optical observation
- GRB 060209(?): Swift-BAT detection of a possible burst
- GRB 060206: WSRT Radio Observations
- GRB 060203: Swift/UVOT upper limits
- GRB060204a: Swift XRT Source is not GRB Afterglow
- GRB 060204b: pseudo-z from spectral parameters of the prompt emission
- GRB 060204A: ROSAT Pointing
- GRB060204A: Swift/UVOT observations
- GRB 060206: Swift-BAT refined analysis
- GRB060206: Swift XRT Refined Analysis
- GRB060206: Swift XRT Position
- GRB060204a: Swift XRT Detection of an Afterglow Candidate
- GRB060206 - Swift UVOT Confirmation of Optical Afterglow
- GRB060206: Swift-BAT detection of a burst
- GRB 060204C: XRT analysis of Swift J061223.0+701243.9
- BAT GRB 060204C is probably not a GRB
- GRB 060204B: BVRi-band detections of optical afterglow
- GRB 060204A: Swift XRT upper limit
- GRB060204B: Swift/UVOT refined analysis
- GRB 060204C: optical observations
- Swift XRT Observation of GRB 060204C
- GRB 060204B: Swift-BAT refined analysis
- GRB060204B: Swift XRT Team Refined Analysis
- GRB 060204C: OSN limits
- GRB 060204C: Liverpool Telescopes optical limit
- GRB 060204C: ROTSE-III Optical Limits
- GRB 060204C: Swift-BAT detection of a burst
- GRB 060124: Radio Observations
- GRB060204B: Faulkes OT candidate
- GRB 060204B: ART optical limit
- GRB060204B, optical observation
- GRB060204B - SDSS pre-burst observations
- GRB 060203: Swift-BAT refined analysis
- GRB 060204B: Swift detection of a burst
- GRB 060203: RTT150 optical observations
- GRB060203: Swift XRT Team Refined Analysis
- GRB060203 - Swift UVOT observation
- Swift-BAT trigger is GRB 060203
- GRB 060203: IR Counterpart
- GRB060203: Observations with SARA
- GRB 060203: P60 Confirmation of Optical Afterglow
- Possible GRB 060203: candidate optical counterpart
- Swift BAT Trigger 180151: Swift XRT source detection
- Possible GRB 060203: optical observations at Asiago
- Swift-BAT trigger 180151 is unknown origin at this time