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"27392 results found.
- 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
- GRB 080916C: Swift/XRT detection of possible afterglow
- GRB 080916B: Swift UVOT Refined Analysis
- GRB 080916B, Swift-BAT 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 080916A, Swift-BAT refined analysis
- GRB 080916B: Swift-XRT afterglow detection
- GRB 080916A: Enhanced Swift-XRT position
- GRB 080916: REM detection of the NIR afterglow
- GRB 080916: REM candidate afterglow
- GRB 080916: Swift detection of a burst with optical afterglow
- GRB 080915B, Swift-BAT refined analysis
- GRB 080912 : Fermi GBM detection
- GRB 080915: REM NIR early observations
- 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 080913: Swift-XRT refined analysis
- GRB080913: Swift/UVOT Upper Limits
- GRB 080913, Swift-BAT refined analysis
- GRB 080913: VLT/FORS2 observations
- GRB 080913: REM NIR early observations
- GRB 080913: Enhanced Swift-XRT position
- 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
- SGR J0501+4516: radio pulsar searches with GBT and WSRT
- 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
- GRB 080906: Refined Swift/UVOT Observations
- GRB 080906: Swift-XRT Refined Analysis
- GRB 080906, Swift-BAT refined analysis
- GRB 080905A: optical afterglow
- GRB 080906: GROND observations of the optical/NIR afterglow
- GRB 080905B: Refined UVOT Analysis
- GRB 080905B: VLT redshift
- GRB 080905A: NOT and VLT observations
- GRB 080905B: Enhanced Swift-XRT position
- GRB 080905B, Swift-BAT refined analysis
- GRB 080905A, Swift-BAT refined analysis
- GRB 080906: Swift detection of a burst with optical afterglow
- GRB 080905A: Swift-XRT Refined Analysis
- GRB080825C: Fermi-LAT observations
- GRB 080905B: Swift detection of a burst with possible optical counterpart
- GRB 080905: Swift detection of a probably-short burst
- GRB 080903: Swift/UVOT Observations
- GRB 080903: Swift-XRT Refined Analysis
- GRB 080903: Enhanced Swift-XRT position
- GRB 080903, Swift-BAT refined analysis
- GRB 080903: optical observations
- GRB 080903: Liverpool Telescope observations
- GRB 080903: Optical afterglow candidate
- GRB 080903: TAROT Calern observatory optical observations
- GRB 080903: Swift detection of a burst
- GRB 080830: Fermi Gamma-ray Burst Monitor detection
- SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
- SGR 0501+4516: preliminary results of the first XMM-Newton observation
- nIR observations of SGR 0501+4516
- SGR 0501+4516: Confirmation of the NIR counterpart
- GRB080828: Swift/UVOT Upper Limits
- SGR 0501+4516: Detection of possible optical counterpart
- GRB080825B: Swift/UVOT Upper Limits
- GRB 080828: Swift-XRT detection of a possible X-ray afterglow
- VLA non-detection of SGR 0501+4516
- Swift trigger 322590: BAT detection of a possible burst
- GRB 080828: SuperAGILE GRB Localization
- Enhanced Swift-XRT position of SGR 0501+4516
- SGR 0501+4516: GMRT Radio Observation at 618 MHz
- GRB080823: Fermi Gamma-ray Burst Monitor detection
- GRB 080824: Fermi Gamma Ray Burst Monitor detection
- Konus-Wind observation of GRB 080825B
- GRB080825C: GLAST Burst Monitor detection
- GRB 080825B: Swift-XRT team analysis
- SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
- Suzaku ToO Observation of SGR 0501+4516
- SGR 0501+4516: radio pulsar searches with GBT and WSRT
- GRB 080825B: GRB Localization by SuperAGILE