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"41700 results found.
- GRB 150626A: Swift detection of a burst
- Swift Trigger 646423 is GS 1354-645
- Fermi Gamma-ray Burst Monitor triggers that are not GRBs
- V404 Cyg: MASTER Swift, Integral alert observations
- Fermi Gamma-ray Burst Monitor triggers bn150622899 and bn150623043 are not GRBs
- GRB 150622A: Swift-XRT observations
- GRB 150622A: Tiled Swift observations
- GRB 150622A: MAXI/GSC detection
- Swift Trigger 645340 was Sco X-1
- Swift Trigger 645340: a possible GRB
- Trigger 645176: Swift detection of V404 Cyg
- V404 Cyg: Fermi GBM observations
- GRB 150616A: Watcher optical upper limit
- Swift triggers again on V404 Cyg
- Swift Trigger 644520 is V404 Cyg
- GRB 150616A: Swift/UVOT Upper Limits
- GRB 150616A: Swift-BAT refined analysis
- V404 Cyg outburst (Swift trigger 643949 ): TSHAO optical observations
- GRB 150616A: Swift-XRT refined Analysis
- Konus-Wind observation of Galactic transient V404 Cyg in outburst
- GRB 150616A: Swift detection of a burst
- Fermi GBM trigger 150616734 is not a GRB
- Fermi GBM trigger 150616594 is not a GRB
- V404 Cyg: Swift/UVOT Detection
- Fermi Gamma-ray Burst Monitor triggers bn150615791 and bn150615798 are not GRBs
- Optical follow-up of Swift trigger on V404 Cyg
- GRB 150615A, Swift-BAT refined analysis
- Swift trigger 643949 is V404 Cyg
- GRB 150615A: Swift-XRT refined Analysis
- Fermi GBM trigger 150615574 is not a GRB
- GRB 150608A: Swift-XRT follow-up observations
- GRB 150615A: Swift/UVOT Detection
- GRB 150615A: Swift detection of a burst
- Fermi GBM trigger 150613619 is not a GRB
- Fermi GBM trigger 150612648 is not a GRB
- GRB 150608A: MITSuME Akeno optical upper limits
- Trigger 643078: Swift detection of H1743-322
- Konus-Wind observation of GRB 150608A
- GRB 150608A: Swift-XRT afterglow detection
- Fermi Gamma-ray Burst Monitor trigger 455474712 / 150608698 is not a GRB
- GRB150607A: AAO and CrAO optical observations
- GRB150607A: Discovery Channel Telescope Optical Observations
- GRB 150608A: Tiled Swift observations
- GRB 150608A: MAXI/GSC detection
- Konus-Wind observation of GRB 150607A
- GRB 150607A: Swift-XRT refined Analysis
- GRB 150607A: Swift/UVOT Detection
- GRB 150607A: NOT optical observations
- GRB 150607A: Swift-BAT refined analysis
- GRB 150607A: Fermi GBM Detection
- GRB 150607A: Swift detection of a burst with an optical counterpart
- GRB 150518A: possible SN observations
- Swift trigger 642453 is not an astrophysical source
- Swift Trigger 642453: a possible GRB
- Konus-Wind observation of GRB 150530A
- GRB 150530B: Swift-XRT observations
- GRB 150527A: Continued RATIR Observations
- Swift Triggers 642296 and 642297 are not GRBs
- GRB 150530B: Swift ToO observations
- GRB 150530B detected in ground analysis of BAT data
- GRB 150530A: RATIR Optical Observations
- GRB 150530A: Swift-XRT refined Analysis
- GRB 150530A: Swift/UVOT Upper Limits
- GRB 150530A: Fermi GBM observation
- GRB 150530A: Swift-BAT refined analysis
- GRB 150530A: Swift detection of a burst
- Fermi GBM trigger 150529948 is not a GRB
- GRB 150513A: Swift-XRT observations
- Konus-Wind observation of GRB 150527A
- GRB 150527A: Swift-XRT refined Analysis
- GRB 150527A: MITSuME Okayama upper limits
- GRB 150527A: Swift/UVOT Upper Limits
- GRB150527A: REM - NIR afterglow
- GRB 150527A: Swift-BAT refined analysis
- GRB 150527A: Fermi GBM observation
- GRB 150527A: LCOGT McDonald observations
- GRB 150527A: RATIR Afterglow Detection
- GRB 150523A: Suzaku WAM observation of the prompt emission
- GRB 150527A: Swift detection of a burst
- GRB 150523A: Swift ToO observations
- GRB 150523A: Swift/UVOT Detection
- GRB 150513A: request for X-ray follow up
- Konus-Wind observation of GRB 150523A
- GRB 150523A: LCOGT FTS afterglow confirmation
- GRB 150523A: LCOGT Cerro-Tololo optical afterglow candidate
- Confirmation that Swift Trigger 641332 is not astrophysical
- GRB 150523B: Swift ToO observations
- GRB 150523A: Fermi-LAT detection
- GRB 150523A: Fermi GBM detection
- Swift trigger 641332 is probably not an astrophysical source
- GRB 150518A: Continued RATIR optical observations
- GRB 150518A: MAXI-GSC further analysis
- GRB 150518A: 6.0 GHz VLA detection
- Disreqard the recent cluster of Swift-related GCN Circulars
- GRB 150518A: MITSuME Akeno Optical observation
- GRB 150518A: Mondy optical observations
- GRB 150518A: AMI 15 GHz detection of possible radio counterpart
- GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
- Konus-Wind observation of GRB 150518A
- GRB 150518A: Swift-XRT follow-up observations