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"32495 results found.
- 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 080915A: GROND upper limits
- GRB080913: Swift-BAT spectral lag
- 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
- 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
- GRB080916A: Spectroscopic redshift
- GRB 080916C: Swift/XRT detection of possible afterglow
- GRB 080916B: Swift UVOT Refined Analysis
- IPN Triangulation and Energy Spectrum of GRB080916C
- GRB 080916B, Swift-BAT refined analysis
- GRB080916A: Refined Swift/UVOT Observations
- GRB 080915a, SMARTS optical/IR observations
- GRB 080916C: Fermi LAT observation
- GRB 080916A: Swift XRT refined analysis
- GRB 080916A, Swift-BAT refined analysis
- GRB 080916: REM detection of the NIR afterglow
- GRB 080916: REM candidate afterglow
- GRB 080915B, Swift-BAT refined analysis
- 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
- SGR 0501+4516 : P200 i-band observations
- GRB 080915: ROTSE-III Optical Limits
- GRB 080913: Swift-XRT refined analysis
- GRB 080913: VLT/FORS spectrum
- GRB080913: Swift/UVOT Upper Limits
- GRB 080913: GROND photo-z
- GRB 080913, Swift-BAT refined analysis
- GRB 080913: VLT/FORS2 observations
- GRB 080913: REM NIR early observations
- GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
- GRB 080906: Watcher observations
- Swift-BAT/-XRT refined analysis on trigger 324362 (LS I +61 303)
- SGR J0501+4516: radio pulsar searches with GBT and WSRT
- Swift trigger 324362 (LS I +61 303 ?): XRT
- GRB080905A: Swift/UVOT Upper Limits
- GRB 080905B: Watcher optical detection
- GRB 080905B: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: Fermi Gamma-ray Burst Monitor detection
- GRB 080905A: Enhanced Swift-XRT position
- 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
- 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: Swift-XRT Refined Analysis
- GRB 080905B: VLT redshift
- GRB 080905A: NOT and VLT observations
- GRB 080905B, Swift-BAT refined analysis
- GRB 080905A, Swift-BAT refined analysis
- GRB 080905A: Swift-XRT Refined Analysis
- GRB 080825C: Fermi GBM Spectral Analysis
- GRB080825C: Fermi-LAT observations
- GRB 080903: Swift/UVOT Observations
- GRB 080903: Swift-XRT Refined Analysis
- GRB 080903, Swift-BAT refined analysis
- GRB 080903: optical observations
- GRB 080903: Liverpool Telescope observations
- GRB 080903: Astrotel-Caucasus optical observations
- GRB 080903: Optical afterglow candidate
- GRB 080903: ROTSE-III Optical Limits
- Recent VLA non-detection of SGR 0501+4516
- 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
- INTEGRAL ToO observation of SGR0501+4516
- SGR 0501+4516: Confirmation of the NIR counterpart
- GRB080828: Swift/UVOT Upper Limits
- SGR 0501+4516: Detection of possible optical counterpart
- SGR 0501+4516: WHT observations of the possible near-infrared counterpart
- GRB080825B: Swift/UVOT Upper Limits
- GRB 080828: Swift-XRT detection of a possible X-ray afterglow
- Swift-BAT trigger 322590 is not a GRB
- VLA non-detection of SGR 0501+4516
- Radio Detection of SGR 0501+4516: Retraction
- SGR 0501+4516: Decline in Activity
- SGR 0501+4516: Proximity to supernova remnant HB9
- Enhanced Swift-XRT position of SGR 0501+4516
- SGR 0501+4516: GMRT Radio Observation at 618 MHz
- GRB 080825B: pseudo-z= 0.83 from prompt emission spectrum
- Konus-Wind observation of GRB 080825B
- GRB 080825B: Swift-XRT team analysis
- SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
- Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts