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"28082 results found.
- 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
- Swift detection of flare on CC Eri
- GRB 081016: A long GRB discovered by INTEGRAL
- Trigger 331721 Due to Swift startracker loss-of-lock
- Detection of flare star Algol in Swift-BAT slew data
- GRB 081009: Fermi GBM detection
- GRB 081012: GROND upper limits
- Swift-BAT triggered on the flare star Algol
- GRB 081012: Fermi GBM detection
- GRB 081007 and GRB 081007B: Fermi GBM detection
- GRB 080430: optical observations
- GRB 081012: Observations from NOT
- GRB 081012: Swift/XRT detection
- GRB 081012, Swift-BAT refined analysis
- 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
- GRB 081008, Swift-BAT refined analysis
- GRB 081008: Swift-XRT Refined Analysis
- GRB081008: Swift/UVOT observations
- GRB 081008: Enhanced Swift-XRT position
- 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: Enhanced Swift-XRT position
- GRB 081007, Faulkes Telescope North optical 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
- 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
- GRB 081003A: Swift-XRT Team position and analysis
- GRB 081003B: a long GRB detected with INTEGRAL
- GRB 080928: Fermi GBM detection
- GRB 081003: A long GRB discovered by INTEGRAL
- SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
- Trigger 330353: Swift detection of a Galactic short soft burst
- GRB 081001: Observations from OSN
- GRB 080925: Suzaku WAM observation of the prompt emission
- GRB 081001: Swift UVOT Observations
- GRB 081001: Swift-XRT position
- GRB081001: SuperAGILE Localization of a long GRB
- GRB 080928: Watcher observations
- GRB 080927: Fermi GBM detection
- GRB 080928: VLT redshift
- GRB 080928: Swift-XRT refined analysis
- GRB 080928, Swift-BAT final refined analysis
- GRB 080928: GROND DETECTION
- GRB 080928: Enhanced Swift-XRT position
- GRB 080928, Swift-BAT initial refined analysis
- GRB 080928A: ROTSE-III Confirmation of Optical Counterpart
- GRB 080928: Swift detection of a burst with an optical counterpart
- GRB 080925: Fermi GBM Detection
- GRB 080920: Fermi GBM detection
- GRB080922, optical upper limit
- Swift trigger 325707: Swift/UVOT Upper Limits
- Swift trigger 325707: Swift-XRT upper limit
- Swift detection of a possible GRB (trigger 325707)
- GRB080916A: Suzaku WAM observation of the prompt emission
- GRB 080922: Swift/UVOT Upper Limits
- GRB080922: Swift-XRT upper limit
- GRB080922: A long GRB detected by INTEGRAL
- GRB 080913B: Fermi GBM detection
- Trigger 324561: IGR J08408-4503 detected by Swift
- GRB 080919: Swift-XRT refined analysis
- GRB 080919, Swift-BAT 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: Fermi GBM detection
- GRB 080916C: Swift UVOT Refined Analysis
- GRB 080916C: Swift XRT refined analysis
- GRB 080916B: Swift-XRT refined analysis
- Konus-Wind observation of GRB 080916A
- GRB 080916C: GROND Detection of the Optical Afterglow Candidate
- GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 080916C: Enhanced XRT position
- GRB080916A: Spectroscopic redshift