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.
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"20366 results found.
- GRB 100302A: Swift detection of a burst
- GRB 100206A: optical observations in CrAO
- GRB 100206A: optical observations in Terskol
- GRB 100213B: Mondy optical observations
- GRB 100219A: optical observations
- GRB 100225A: Fermi LAT detection
- GRB
- GRB100219A Akeno and Okayama MITSuME Optical Observation
- GRB 100219A: GROND observations
- GRB 100219A: NOT OA observations
- GRB 100219A: Enhanced Swift-XRT position
- GRB 100219A: Swift/UVOT Detection of the Optical Afterglow
- GRB 100216A: XRT Refined Analysis
- GRB 100219A: Pre-explosion imaging and host candidate
- GRB 100219A: Swift/UVOT Detection of a Source near the XRT Position
- GRB 100219A: Swift detection of a burst
- GRB 100216A: Keck imaging
- GRB 100213A: Swift-BAT lag analysis indicates probably SHB
- GRB 100213B: GRT Optical Observation
- GRB 100213A: GRT Optical Observation
- GRB 100213B: Enhanced Swift-XRT position
- GRB 100213B: Gemini-N Observations
- GRB 100213B: Swift/UVOT Upper Limits
- GRB 100213A: Swift/UVOT Upper Limits
- GRB 100213B: PAIRITEL NIR Upper Limits
- GRB 100213A: Enhanced Swift-XRT position
- GRB 100213A: SARA observations
- GRB 100213B: NOT optical observations
- GRB 100213B: Swift detection of a burst
- GRB 100213A: Swift detection of a burst
- Swift/UVOT observations of GRB120212A
- GRB 100212A: Enhanced Swift-XRT position
- GRB 100212A: candidate optical afterglow
- GRB 100212A: Swift detection of a burst
- GRB 091127: Detection of a Supernova
- GRB 100205A: Keck limits on an underlying host galaxy
- GRB 100206A: GROND upper limits
- GRB 100206A: Gemini-North observations
- GRB 100206A: Swift/UVOT Upper Limits
- GRB 100131A: MASTER-Net optical alert observations
- GRB 100206A: YNAO-GMG observations
- GRB 100206A: MASTER-Net optical alert observations
- GRB 100206A: PAIRITEL Photometry of Host Candidate
- GRB100206: MITSuME optical upper limits
- GRB 100206A: NOT NIR observations
- GRB 100206A, RIMOTS optical upper limits
- GRB 100205A: GROND upper limits
- GRB 100206A: Optical limit
- GRB 100206A: Enhanced Swift-XRT position
- GRB 100206A: Pre-explosion imaging and host candidate
- GRB 100206A: Swift detection of a short hard burst
- GRB100205A: CFHT z'-band observation
- GRB 100205A: Gemini-N + NIRI photometry
- GRB 100130B: Fermi GBM detection
- GRB 100113A: Fermi GBM detection
- GRB 100205A: Swift UVOT upper limits
- GRB 100203A: Swift XRT and UVOT refined analyses
- GRB 100205A: Enhanced Swift-XRT position
- GRB 100205A Gemini-North IR afterglow candidate
- GRB 100205A: Gemini-South Observations
- GRB 100205A: Super-LOTIS early observations
- GRB 100205A: NOT optical observations
- GRB 100205A: Swift detection of a burst
- GRB 100203A Detected in Ground Analysis of BAT Data
- Short X-ray Transient detected by MAXI/GSC
- GRB 100122A: MASTER-Net optical observations
- GRB 100116A: Suzaku WAM observation of the prompt emission
- GRB 100119A: Swift-BAT refined analysis
- Swift/UVOT refined analysis of GRB100117A
- GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
- GRB100117A: Possible afterglow from NOT observation
- GRB 100117A: Swift detection of a short hard burst
- GRB 100115A: Gemini-N photometry
- GRB 100115A: Enhanced Swift-XRT position
- GRB 100116A: Fermi LAT detection
- GRB 100115A: SARA Astrometry
- GRB 100115A: SARA Afterglow Candidate
- GRB 100115A: Swift/UVOT Upper Limits
- GRB 100115A: Swift-XRT candidate afterglow
- GRB 100115A detected in ground analysis of Swift-BAT data
- GRB 100111A: PAIRITEL NIR Upper Limits
- GRB 100111A: Swift UVOT Refined Analysis
- GRB 100111A: Enhanced Swift-XRT position
- GRB 100111A: NOT optical observations
- GRB 100111A: Swift detection of a burst with an optical afterglow
- Swift/BAT Detects an Outburst from XTE J1901+014
- GRB 100103A: GROND Upper Limits
- GRB 100103A - UVOT-enhanced XRT position
- GRB 100103A: Swift/XRT position
- GRB 091231: GROND NIR observations
- Swift Trigger 381591: Uncatalogued UVOT Source
- GRB 091230: Swift/UVOT Observations
- Trigger 381591: Swift detection of a possible burst
- GRB 091230: Swift-XRT observation
- GRB 091230: GROND optical/NIR afterglow candidate
- Swift Trigger 381434 is not a GRB
- Trigger 381434: Swift detection of a possible burst
- GRB 091221: Skynet/PROMPT Detections
- GRB 091117: Swift-XRT late time observations
- GRB 091221: Swift/UVOT refined analysis