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"27021 results found.
- GRB081006B: Fermi GBM detection
- GRB081006: Fermi GBM detection
- GRB081007: Swift/UVOT Observations
- GRB 081007, Swift-BAT refined analysis
- GRB 081007: Early RAPTOR measurements of optical counterpart
- GRB 081007: Swift-XRT Team refined analysis
- 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
- 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
- AXP 1E1547.0-5408: Swift-XRT Team refined analysis
- GRB 081003A: Swift-XRT Team position and analysis
- Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
- 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 080925: Suzaku WAM observation of the prompt emission
- GRB 081001: Swift-XRT position
- GRB081001: optical limit from ASH-Centurion
- GRB 080928: Watcher observations
- GRB 080927: Fermi GBM detection
- GRB 080928: VLT redshift
- GRB 080928: Swift/UVOT observations
- GRB 080928, Swift-BAT final refined analysis
- GRB 080928: GROND DETECTION
- 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-BAT trigger 325707 is not a GRB
- 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
- GRB080922: Swift-XRT upper limit
- GRB 080913B: Fermi GBM detection
- Trigger 324561: IGR J08408-4503 detected by Swift
- GRB 080916C: Fermi GBM Spectral Analysis
- GRB 080919: Swift/UVOT Refined Analysis
- GRB 080919: Swift-XRT refined analysis
- GRB 080919, Swift-BAT refined analysis
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080916C: GROND Confirmation of the Optical Afterglow
- GRB 080919: Swift detection of a short burst
- GRB 080915A: GROND upper limits
- GRB 080916A: GROND lightcurve
- GRB 080916A: Rapid PROMPT Observations
- GRB 080916A: Fermi GBM detection
- GRB 080916C: Swift XRT refined analysis
- GRB 080916B: Swift-XRT refined analysis
- Konus-Wind observation of GRB 080916A
- Konus-Wind observation of GRB 080916C
- GRB 080916C: GROND Detection of the Optical Afterglow Candidate
- GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 080916B: Swift UVOT Refined Analysis
- GRB 080916B, Swift-BAT refined analysis
- GRB080916A: Refined Swift/UVOT Observations
- GRB 080916C: Fermi LAT observation
- GRB 080916C: Fermi GBM Detection
- GRB 080916A, Swift-BAT refined analysis
- GRB 080916B: Swift-XRT afterglow detection
- GRB 080916B: Swift detection of a burst
- GRB 080916: Swift detection of a burst with optical afterglow
- GRB 080915B, Swift-BAT refined analysis
- GRB 080912 : Fermi GBM detection
- GRB 080915B: Swift detection of a burst
- GRB 080915: Swift/UVOT Upper Limits
- GRB 080915: Swift-XRT afterglow detection and analysis
- GRB 080915, Swift-BAT refined analysis
- GRB 080915: ROTSE-III Optical Limits
- GRB 080915: Swift detection of a burst
- GRB 080913: Swift-XRT refined analysis
- GRB080913: Swift/UVOT Upper Limits
- GRB 080913, Swift-BAT refined analysis
- GRB 080913: VLT/FORS2 observations
- GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
- GRB 080913: Swift detection of a burst
- GRB 080906: Watcher observations
- Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
- GRB 080906B: Fermi GBM detection
- GRB 080905C: Fermi GBM detection
- Swift trigger 324362 (LS I +61 303 ?): XRT
- Swift trigger 324362 (LS I +61 303 ?)
- GRB080905A: Swift/UVOT Upper Limits
- GRB 080905B: Watcher optical detection
- GRB 080904: Fermi Gamma-ray Burst Monitor detection
- GRB 080905B: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: MITSuME Akeno optical upper limits
- Swift Trigger 324122 is again known source Swift J1842.5-1124
- Swift Trigger 324116 is known source again
- Swift Trigger 324112 is known source Swift J1842.5-1124
- GRB 080906: Refined Swift/UVOT Observations