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"19875 results found.
- GRB 060211A: Further refined analysis of the Swift burst
- GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
- 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: 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
- 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
- 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
- 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
- GRB 060202: Refined analysis of the Swift-BAT burst
- GRB060202, optical observation
- GRB 060202: Swift/UVOT upper limits
- GRB 060202: Swift XRT Team Refined Analysis
- GRB060202: Faulkes North observation
- GRB 060202: Swift detection of a burst
- GRB 060130: Swift/XRT observation
- GRB 060123: VLA Radio Observations
- Possible GRB 051221B: MDM Correction
- GRB 060123: Swift refined analysis of an unusual GRB
- GRB060124, BVRcIc field calibration
- GRB060105: refined analysis of the Suzaku observation
- GRB 060124: HETE detection and spectrum of the main peak
- Konus-Wind observation of GRB 060124
- GRB060124: detailed XRT analysis
- GRB 060124 Optical Observations
- GRB 060124: R band Observations
- GRB 060124: Extremely long burst, Swift-BAT refined analysis
- GRB 060123: Swift detection of a very long, faint burst
- GRB 060124: TAROT optical limits
- GRB 060124: Swift/UVOT Observation
- GRB 060124: Confirmation of the Afterglow
- GRB 060124: XRT position
- GRB 060124: Optical Observations at Tautenburg
- GRB 060117: Suzaku WAM observation of the prompt emission
- GRB060124:MASTER optical observation
- GRB 060111B: Suzaku WAM observation of the prompt emission
- GRB 060124: Swift-BAT detection of a burst
- GRB 060116: Radio Detection
- GRB 060116: MARGE optical observations
- GRB 060121: Swift/UVOT upper limits
- GRB 060121: Liverpool Telescopes optical limits
- GRB 060121: Swift XRT refined analysis
- GRB 060121: Swift XRT refined position