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"24838 results found.
- GRB 190110A, Swift-BAT refined analysis
- Correction to GCN Circular 23663: GRB 190109A: Swift UVOT Upper Limits
- GRB 190110A: Fermi GBM detection
- GRB 190109B: Fermi GBM observation
- GRB 190109B: Swift/UVOT Upper Limits
- GRB 190109A: Swift/UVOT Upper Limits
- GRB 190109B: Swift-XRT refined Analysis
- GRB 190106A: optical observations, possible jet break detection
- GRB 190106A: Liverpool Telescope observations
- GRB 190109B: Swift-BAT refined analysis
- GRB 190109B: COATLI Optical Observations
- GRB 190109B: Mondy optical upper limit
- GRB 190109A: Swift-BAT refined analysis
- GRB 190109B: Enhanced Swift-XRT position
- GRB 190109B: Swift-XRT observations
- INTEGRAL Weak#8189: AROMA-N Optical Observation
- GRB 190109B: Swift detection of a burst
- CALET Gamma-Ray Burst Monitor: Policy change in the GCN circulars
- IPN triangulation of GRB 190103A (long)
- GRB 190109A: Swift-XRT refined Analysis
- GRB 190109A: Enhanced Swift-XRT position
- GRB 190109A: Swift detection of a burst
- IceCube-190104A: Swift-XRT observations
- GRB 190106A: NEXT-0.6m and Xinglong-2.16m photometric single powerlaw decay
- GRB 190106A: Swift-XRT refined Analysis
- GRB 190106A: OASDG optical observations
- GRB 190106A: Swift/UVOT Detection
- GRB 190106A: Swift-BAT refined analysis
- GRB 190106A: Bassano Bresciano Observatory optical detection
- Fermi GBM Observations of IceCube-190104A
- GRB 190106A : TSHAO optical observations
- GRB 190106A: Enhanced Swift-XRT position
- GRB 190106A: GMG detection
- GRB 190106A: Swift detection of a burst with an optical counterpart
- SWIFT GRB190106.57 Global MASTER-Net OT detection
- Search for counterpart to IceCube-190104A with ANTARES
- IceCube-190104A: MASTER optical observation
- GRB 190103A: AstroSat CZTI detection
- Fermi LAT Gamma-ray Observations of IceCube-190104A
- GRB 190103B: Bassano Bresciano observatory upper limit
- GRB 190103B: Swift-BAT refined analysis
- GRB 190103B: Swift-XRT refined Analysis
- GRB 190103B: Enhanced Swift-XRT position
- GRB 190103B: Swift detection of a burst
- GRB 181231A: Fermi GBM detection
- GRB 181228A: Mondy and AbAO optical upper limits
- GRB 181225A: further Swift-XRT observations
- GRB 181228A: possible NOT optical detection
- GRB 181228A: Xinglong-2.16m optical upper limit
- GRB 181227A: Global MASTER Net oprtical inspection
- Swift Trigger 880127 is not a GRB
- GRB 181228A: Swift-XRT refined Analysis
- GRB 181228A: Swift-BAT refined analysis
- GRB 181222B: Swift follow-up observations of MASTER optical transient J204928.79+245744.0
- GRB 181228A: Swift/UVOT Upper Limits
- GRB 181228A: TSHAO optical upper limit
- GRB 181228A: Fermi GBM observation
- GRB 181228A: Global MASTER Net OT detection
- GRB 181228A: REM NIR detection
- GRB 181228A: Enhanced Swift-XRT position
- GRB 181225A: KAIT Follow-Up Observations with Upper Limit
- GRB 181228A: Swift detection of a burst
- GRB 181227A: Fermi GBM detection
- GRB 181225A: Swift observations and X-ray candidate afterglow
- GRB 181225A: Fermi GBM detection
- GRB 181225A: Fermi-LAT Detection
- GRB 181224A: Swift-BAT refined analysis
- GRB 181224A: Swift detection of a burst
- GRB 181222B : Fermi GBM detection
- Swift Trigger 878504 is not astrophysical
- GRB 181222A: Fermi GBM observation
- GRB 181222A: MAXI/GSC detection
- GRB 181217A: Insight-HXMT/HE detection
- GRB 181213A: Swift/UVOT Observations
- GRB 181213A: Mondy optical observations
- GRB 181213A: continued TSHAO optical observations
- GRB 181213A:Insight-HXMT/HE detection
- GRB 181212A:Insight-HXMT/HE detection
- GRB 181213A: AbAO optical observations
- GRB 181213A: HMM-0.5m, NEXT-0.6m, CNEOST-1m optical observations
- GRB 181213A: NOT optical observations
- GRB 181213A: Swift-XRT refined Analysis
- GRB 181213A: Enhanced Swift-XRT position
- IPN Triangulation of GRB 181212A (long)
- GRB 181213A: Swift-BAT refined analysis
- GRB 181213A : TSHAO optical observations
- GRB181213A: Swift/UVOT Detection
- GRB 181213A: Swift-XRT observations
- GRB 181213A: Swift detection of a burst
- GRB 181212A: Fermi GBM Detection
- GRB 181126B: KAIT Follow-Up Observations of a Fermi Short GRB (Trigger 564897175)
- MASTER OT J063515.49-624002.9 of Fermi trigger 565936249: optical observations in SAAO
- MASTER: OTs detection during Fermi alert trigger 565936249 early observations
- INTEGRAL observations of the events in the GWTC-1 catalog
- GRB 181203A: GROND detection of the afterglow
- GRB 181126B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 564897175)
- GRB 181205A: a long GRB detected by INTEGRAL
- GRB181201A: Optical afterglow measurements by GROWTH-India
- Swift Trigger 874754 is likely not an astrophysical event
- Fermi-GBM Observations During Four New GW-Detected BBH Mergers (Correction)