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"27394 results found.
- GRB 190220A: Enhanced Swift-XRT position
- GRB 190219A: NOT optical afterglow candidate
- GRB 190219A: NEXT-0.6m optical upper limit
- GRB 190219A: Swift-XRT refined Analysis
- GRB 190220A: Swift detection of a burst with an optical counterpart
- GRB 190219A: Enhanced Swift-XRT position
- GRB 190219A: BOOTES-1 optical limits
- GRB 190219A: Swift detection of a burst
- Trigger 889483: Swift detection of Swift J1858.6-0814
- GRB 190215A: Insight-HXMT/HE detection
- GRB 190215A: Fermi GBM detection
- GRB 190212A: Insight-HXMT/HE detection
- GRB190211A: GROWTH-India detection of optical afterglow
- GRB 190211A: Tautenburg observations
- GRB 190211A: Swift/UVOT Detection
- GRB 190211A: NOT optical observations
- GRB 180703A: VLT/MUSE host galaxy redshift measurement
- GRB 190211A: Swift-XRT refined Analysis
- GRB 190211A: Swift-BAT refined analysis
- GRB 190211A: NEXT-0.6m optical afterglow detection
- GRB 190211A: Swift detection of a burst
- Trigger 888312: Swift detection of 4U 1901+03
- GRB 190202A: Terskol 2-m optical observations
- IPN Triangulation of GRB 190206A (short/extremely bright)
- GRB 190203A: Mondy optical observations
- GRB190202A: GROWTH-India detection of optical afterglow
- GRB 190203A: Swift-BAT refined analysis
- GRB 190204A: Swift-BAT refined analysis
- GRB 190202A: Xinglong-2.16m optical observations
- GRB 190202A: SAO RAS further optical observations
- Konus-Wind observation of GRB 190204A
- GRB 190204A: SAO RAS optical observations
- GRB 190204A: Mondy optical upper limit
- GRB190203A: UVOT analysis
- GRB 190203A: COATLI Optical Observations
- GRB 190204A: Swift/UVOT Detection
- GRB 190204A: Enhanced Swift-XRT position
- GRB 190204A: COATLI Optical Detection of the Fading Afterglow
- GRB 190203A: Liverpool Telescope near-IR observations
- GRB 190203A: Swift-XRT refined Analysis
- GRB 190204A: Swift-XRT refined Analysis
- Swift Trigger 887541: MASTER inspect
- GRB 190204A: MAXI/GSC detection
- GRB 190202A: R and I band observation from HCT
- GRB 190204A: Swift detection of a burst with a possible optical counterpart
- GRB 190203A: MASTER OT detection
- Swift Trigger 887541: Swift detection of Swift J1728.9-3613
- GRB 190203A: Enhanced Swift-XRT position
- GRB 190203A: SAO RAS optical observations, afterglow fading
- GRB 190203A: Koshka Zeiss-1000 optical upper limit
- GRB 190203A: Swift detection of a burst with an optical counterpart
- GRB 190202A: SAO RAS optical observations
- GRB 190202A: TSHAO optical observations
- GRB 190202A: Swift-XRT refined Analysis
- GRB 190202A: LCO-CTIO optical observations
- GRB 190202A: Fermi GBM observation
- GRB 190202A, Swift-BAT refined analysis
- GRB 190202A: Swift/UVOT Detection
- GRB 190202A: GOTO optical observations
- GRB 190202A: Enhanced Swift-XRT position
- GRB 190202A: Koshka Zeiss-1000 optical observations
- GRB 190202A: Swift detection of a burst with an optical counterpart
- Fermi GBM trigger 570716645/190201517 is not a GRB
- GRB 190131A: Insight-HXMT/HE detection
- GRB 190129B: Insight-HXMT/HE detection
- GRB 190129B: DDOTI Detection of the Possible Afterglow and Suggestion of Fading
- GRB 190129B: Swift/UVOT Upper Limits
- GRB 190129B: ePESSTO NTT optical observations
- GRB 190129B: MASTER Global Robotic Net optical observation
- GRB 190129B: GROND possible host candidate
- GRB 190129B: Swift-XRT candidate afterglow detection
- Fermi GBM Observations of IceCube-190124A
- GRB 190129A: Fermi GBM detection
- INTEGRAL observation of IceCube-190124A
- GRB 190129A: MAXI/GSC detection
- Trigger 886496: Another Swift trigger on MAXI J1348-630
- Trigger 886486: Swift detection of MAXI J1631-479
- Trigger 886266: Another Swift trigger on MAXI J1348-630
- GRB 190114C: Optical follow-up from HCT
- Swift Trigger 885960: A third Swift trigger on MAXI J1348-630
- Trigger 885807: Swift detection of MAXI J1348-630
- Search for counterparts to IceCube-190124A with IceCube
- Search for counterpart to IceCube-190124A with ANTARES
- Fermi-LAT Gamma-ray Observations of IceCube-190124A
- GRB 190123A: IKI-GRB-FuN optical upper limit
- GRB 190123A: NEXT-0.6m optical limit
- GRB 190114C: CHILESCOPE optical observations
- GRB 190123A: AROMA-N Optical Observation
- GRB 190123A: Swift/UVOT Upper Limits
- GRB 190123A: COATLI Optical Observations
- GRB 190123A: Swift-BAT refined analysis
- GRB 190123A: GMG observational limit
- Trigger 885456: Swift detection of MAXI J1631-479
- GRB 190123A: Swift-XRT refined Analysis
- GRB 190123A: GOTO optical limit
- GRB 190123A: Fermi GBM observation
- GRB 190123A: Enhanced Swift-XRT position
- GRB 190123A: MASTER Global Robotic Net optical observation
- GRB 190123A: Swift detection of a burst
- GRB 190122A: Fermi GBM observation