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"36152 results found.
- GRB 081021: Fermi GBM detection
- GRB081028: UVOT detection of a brightening afterglow
- Swift UVOT observations of GRB081028
- GRB 081028: Swift-XRT refined analysis
- GRB 081028, Swift-BAT refined analysis
- GRB 081028: Enhanced Swift-XRT position
- GRB 081028: TAROT Calern observatory optical observations
- GRB 081028: optical observations at the NOT
- GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
- Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
- Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
- GRB 081028: Swift detection of a burst
- GRB 081025: TLS upper limits
- GRB 081024: No radio detection with the VLA
- GRB081025: RTT150 optical observations
- GRB 081024B: Swift-XRT further observations
- GRB 081025 BAT refined analysis
- Swift UVOT observations of GRB081025
- Swift UVOT observations of GRB081024B
- Konus-Wind observation of GRB 081025
- GRB 081025: Swift-XRT position
- GRB 081024B: Swift-XRT observations
- GRB 081025: Burst detection from Swift-BAT slew data
- GRB 081024B: Fermi Gamma-ray Burst Monitor detection
- Fermi-LAT observation of GRB 081024B
- Swift UVOT observations of GRB 081024
- GRB 081024: Swift-XRT refined analysis
- GRB 081024, Swift-BAT refined analysis
- GRB 081024: Enhanced Swift-XRT position
- GRB 081024: Faulkes Telescope North optical observations
- GRB 081024: KAIT Optical Limits
- GRB 081024: Early Super-LOTIS Observations
- GRB 081024A: ROTSE-III Optical Limits
- GRB 081024: Swift detection of a burst
- GRB 081022, Swift-BAT refined analysis
- GRB 081016A: Swift-XRT refined analysis
- GRB 081022: Swift detection of a burst
- GRB 081012: Swift-XRT Refined Analysis
- Swift trigger 332287 is not a GRB
- GRB 081012 - Enhanced Swift XRT position
- GRB 081017, Swift-BAT refined analysis
- GRB 081017: REM early observations
- GRB 081017: Swift detection of a burst
- GRB 081016B, Swift-BAT refined analysis
- GRB 081016B: Swift/UVOT Upper Limits
- GRB 081011: Swift XRT refined analysis
- GRB 081016B: Swift-XRT Team refined Analysis
- GRB 081016B: Enhanced Swift-XRT position
- GRB 081016B: ROTSE-III Optical Limits
- GRB 081016B: Swift detection of a burst
- GRB 081011: Enhanced Swift-XRT position
- GRB 081016: Swift-XRT candidate afterglow detection
- GRB 081016: A long GRB discovered by INTEGRAL
- Trigger 331721 Due to Swift startracker loss-of-lock
- GRB 081009: Fermi GBM detection
- GRB 081012: GROND upper limits
- GRB 081008: Galaxy associated with z=1.967 absorber
- GRB 081012: Fermi GBM detection
- GRB 081007 and GRB 081007B: Fermi GBM detection
- GRB 080430: optical observations
- GRB 081008 optical upper limit
- GRB 081012: Observations from NOT
- GRB 081012: Swift/UVOT analysis of initial observations
- GRB 081012: Swift/XRT detection
- GRB 081012, Swift-BAT refined analysis
- GRB 081012: ROTSE-III Optical Limits
- GRB 081012: Swift detection of a burst
- Revised table for GRB 081011 UVOT detections
- GRB081011: UVOT detection of an optical afterglow
- GRB 081011: Swift/XRT detection
- GRB 081011, Swift-BAT refined analysis
- GRB 081008, SMARTS optical/IR afterglow observations
- GRB 081011: Swift detection of a burst
- GRB 081007: Radio Detection
- Konus-Wind observation of GRB 081001
- GRB 081007: Rapid PROMPT Detections
- GRB 081008, Swift-BAT refined analysis
- GRB 081008: VLT redshift confirmation
- GRB 081008: Swift-XRT Refined Analysis
- GRB081008: Swift/UVOT observations
- GRB 081008: Enhanced Swift-XRT position
- GRB 081008: Gemini-South Absorption Redshiftt
- GRB 081008: VLT/FORS2 spectroscopy
- GRB 081008: Swift detection of a burst with optical afterglow
- GRB 081008: ROTSE-III Detection of Optical Counterpart
- GRB081006B: Fermi GBM detection
- GRB081006: Fermi GBM detection
- GRB081007: Swift/UVOT Observations
- GRB 081007, SMARTS optical afterglow observations
- GRB 081007, Swift-BAT refined analysis
- GRB 081007: Early RAPTOR measurements of optical counterpart
- GRB 081007: Swift-XRT Team refined analysis
- GRB 081007: Gemini-south redshift
- GRB 081007: Enhanced Swift-XRT position
- GRB 081007, Faulkes Telescope North optical observations
- GRB 081007, SMARTS optical/IR afterglow observations
- GRB 081007: REM NIR and optical counterpart
- GRB 081007: Swift detection of a burst with optical afterglow
- GRB081003C: GLAST Burst Monitor detection
- GRB 081003B: TAROT Calern observatory optical observations