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"19598 results found.
- GRB 150323C: Swift-XRT refined Analysis
- GRB 150323C: Xingming upper limit
- GRB 150323A, Swift-BAT refined analysis
- GRB150323C: Fermi GBM detection
- GRB 150323A: KAIT Optical Observations
- GRB 150323C: Nanshan optical afterglow detection
- GRB 150323C: Prompt enhanced Swift-XRT position
- GRB 150323B: Fermi GBM observation
- GRB 150323C: MASTER-net optical observation
- GRB 150323C: Swift detection of a burst
- GRB 150323B: Swift ToO observations
- GRB 150323B detected in ground analysis of Swift-BAT data
- GRB 150323A: Swift-XRT refined Analysis
- GRB150323A: Swift-UVOT detection of the afterglow
- GRB 150323A: Enhanced Swift-XRT position
- GRB 150323A: RATIR Optical Afterglow Observations
- GRB 150323A: P60 Optical Afterglow Candidate
- GRB 150323A: Swift detection of a burst
- Swift Triggers 635788-635794 are probably not real.
- GRB 150318A: Swift-XRT refined Analysis
- Confirmation that Swift trigger 635306 is not an astrophysical source
- GRB 150318A: Skynet PROMPT-CTIO Observations
- GRB 150318A: Swift-BAT refined analysis
- GRB 150318A: Swift/UVOT Upper Limits
- GRB 150318A : GROND upper limits
- Swift Trigger 635306 is probably not an astrophysical source
- GRB 150318A: Enhanced Swift-XRT position
- GRB 150318A: Swift detection of a burst
- GRB 150317A: Swift/UVOT Upper Limits
- GRB 150317A: Swift-XRT refined Analysis
- GRB 150317A: Swift-BAT refined analysis
- GRB 150317A: RATIR Optical Afterglow Detection
- GRB 150317A: Enhanced Swift-XRT position
- GRB 150317A: NOT optical observations
- GRB 150317A: Swift detection of a burst
- GRB 150314A: Early RAPTOR Detection
- Konus-Wind observation of GRB 150314A
- GRB 150314A: Swift-XRT refined Analysis
- GRB 150314A: KAIT Optical Observations
- GRB 150314A Swift-BAT refined analysis
- GRB 150314A: Swift/UVOT Detection
- GRB 150314A: Fermi GBM observation
- GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
- GRB 150314A: Fermi-LAT detection
- GRB 150314A: Enhanced Swift-XRT position
- GRB 150314A: KAIT Optical Candidate
- GRB 150314A: Swift detection of a bright burst
- GRB 150309A: AAO optic upper limit
- GRB 150222A: CrAO optical observation
- Konus-Wind observation of GRB 150309A
- GRB 150309A: CrAO optic upper limit
- GRB 150309A: ISON-Kislovodsk optic upper limit
- GRB 150309A: Swift-BAT refined analysis
- GRB 150309A: Fermi GBM detection
- GRB150309A: Optical observations at Crni Vrh
- GRB 150309A: Swift/UVOT Upper Limits
- GRB 150309A: MASTER prompt optical observation
- GRB 150309A: Swift-XRT refined Analysis
- GRB 150309A : Liverpool Telescope observations
- GRB 150309A: Enhanced Swift-XRT position
- GRB 150309A: BOOTES-1 and -2 upper limit
- GRB 150309A: Swift detection of a burst
- GRB 150305A: a long GRB detected by INTEGRAL
- GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
- Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
- Swift J0045.2+4151: analysis of XMM-Newton archival data
- Further UVOT Observations of Swift J0045.2+4151
- Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
- GRB 150302A: BOOTES-2/TELMA upper limit
- Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
- GRB 150302A, Swift-BAT refined analysis
- GRB 150302A: Swift/UVOT Upper Limits
- GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
- GRB 150302A: Swift-XRT refined Analysis
- GRB 150302A: Enhanced Swift-XRT position
- GRB 150301B: Swift-XRT refined Analysis
- GRB 150220A: further Swift-XRT observations
- GRB 150301B: Swift/UVOT Observations
- GRB 150301B: LCOGT-Sutherland observations
- GRB 150302A: KAIT Optical Upper Limit
- GRB 150302A: UVOT Observations
- GRB 150302A: Swift detection of a burst
- GRB 150301B: Fermi GBM detection
- GRB 150301B: Swift-BAT refined analysis
- GRB 150301B: GROND afterglow observations
- GRB 150301A: Swift/UVOT Upper Limits
- GRB 150301B: Enhanced Swift-XRT position
- GRB 150301A: Swift-BAT refined analysis
- GRB 150301B: MASTER early OT detection
- GRB 150301A: Swift-XRT refined Analysis
- GRB 150301C : (Swift trigger 633105) Swift observations
- GRB 150301B: Swift detection of a burst with an optical afterglow
- Swift Trigger 633173 is probably not an astrophysical source
- GRB 150301A: GROND Observations
- Trigger 633105 is likely not a GRB
- GRB 150301A: Fermi GBM observation
- GRB 150301A: Swift detection of a short burst or new SGR
- Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- GRB 150222A: Further GROND Observations