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"28069 results found.
- GRB 081016: Swift-XRT candidate afterglow detection
- Swift detection of flare on CC Eri
- Detection of flare star Algol in Swift-BAT slew data
- GRB 081009: Fermi GBM detection
- GRB 081012: GROND upper limits
- GRB 081008: Galaxy associated with z=1.967 absorber
- Swift-BAT triggered on the flare star Algol
- GRB 081012: Fermi GBM detection
- GRB 081007 and GRB 081007B: Fermi GBM detection
- 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 detection of a burst
- GRB081011: UVOT detection of an optical afterglow
- GRB 081011: Swift/XRT detection
- GRB 081008, SMARTS optical/IR afterglow observations
- GRB 081011: Swift detection of a burst
- GRB 081007: Radio Detection
- GRB 081007: Rapid PROMPT Detections
- GRB 081008: VLT redshift confirmation
- GRB 081008: Swift-XRT Refined Analysis
- GRB081008: Swift/UVOT observations
- GRB 081008: Enhanced Swift-XRT position
- 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-XRT Team refined analysis
- GRB 081007: Enhanced Swift-XRT position
- GRB 081007, Faulkes Telescope North optical observations
- GRB 081007, SMARTS optical/IR afterglow observations
- GRB 081007: Swift detection of a burst with optical afterglow
- GRB081003C: GLAST Burst Monitor detection
- Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
- AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
- GRB 081003B: Swift-XRT upper limit
- GRB 081003A: OSN optical observations
- GRB 081001: Further observations from OSN
- AXP 1E1547.0-5408: Swift-XRT Team refined analysis
- GRB081003B: Optical limits from Spain
- GRB 081003A: Swift-XRT Team position and analysis
- GRB 080928: Fermi GBM detection
- AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
- SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
- Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
- Trigger 330353: Swift detection of a Galactic short soft burst
- GRB 081001: Observations from OSN
- GRB 081001: Swift UVOT Observations
- GRB 081001: Swift-XRT position
- GRB080928: redshift retraction
- GRB 080928: Watcher observations
- GRB 080927: Fermi GBM detection
- GRB 080928: VLT redshift
- GRB 080928: Swift-XRT refined analysis
- GRB 080928: GROND DETECTION
- GRB 080928: Enhanced Swift-XRT position
- GRB 080928, Swift-BAT initial refined analysis
- GRB 080928: Swift detection of a burst with an optical counterpart
- GRB 080925: Fermi GBM Detection
- GRB 080920: Fermi GBM detection
- Swift trigger 325707: Swift-XRT upper limit
- Swift detection of a possible GRB (trigger 325707)
- GRB 080922: Swift/UVOT Upper Limits
- GRB080922: Swift-XRT upper limit
- GRB 080913B: Fermi GBM detection
- Trigger 324561: IGR J08408-4503 detected by Swift
- GRB 080919: Swift/UVOT Refined Analysis
- GRB 080919: Swift-XRT refined analysis
- GRB 080916C: IRSF/SIRUS NIR Observation
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080919: REM NIR observations
- GRB 080919: Swift detection of a short burst
- GRB 080915A: GROND upper limits
- GRB 080916A: GROND lightcurve
- SGR 0501+4516: preliminary results of the Suzaku ToO observation
- GRB 080916A: Rapid PROMPT Observations
- GRB 080916A: Fermi GBM detection
- GRB 080916C: Swift UVOT Refined Analysis
- GRB 080916C: Swift XRT refined analysis
- GRB 080916B: Swift-XRT refined analysis
- GRB 080916C: GROND Detection of the Optical Afterglow Candidate
- GRB 080916C: Enhanced XRT position
- GRB 080916C: Swift/XRT detection of possible afterglow
- GRB 080916B: Swift UVOT Refined Analysis
- GRB080916A: Refined Swift/UVOT Observations
- GRB 080915a, SMARTS optical/IR observations
- GRB 080916B: Enhanced Swift-XRT position
- GRB 080916C: Fermi LAT observation
- GRB 080916C: Fermi GBM Detection
- GRB 080916A: Swift XRT refined analysis
- GRB 080916B: Swift-XRT afterglow detection
- GRB 080916A: Enhanced Swift-XRT position
- GRB 080916B: Swift detection of a burst
- GRB 080916: REM detection of the NIR afterglow
- GRB 080916: REM candidate afterglow