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"27417 results found.
- GRB 150314A: GMG observation limit
- 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.
- Fermi GBM trigger 150319666 is not a GRB
- 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: 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: 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: P60 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: Swift detection of a bright burst
- Fermi GBM trigger 150312827 is not a GRB
- GRB 150311A: Konus-Wind trigger at 16:16:24 is not a GRB
- GRB 150311A: MAXI/GSC possible afterglow detection
- Konus-Wind observation of GRB 150309A
- GRB 150309A: ISON-Kislovodsk optic upper limit
- Fermi GBM trigger 150311331 is not a GRB
- 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: BOOTES-1 and -2 upper limit
- GRB 150309A: Swift detection of a burst
- GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
- Fermi GBM trigger 150307942 is not a 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
- Fermi GBM trigger 150305751 is not a GRB
- GRB 150301C: VLA Observations
- Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
- BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
- 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 150301B: Swift-XRT refined Analysis
- GRB 150301B: Swift/UVOT Observations
- GRB 150301B: LCOGT-Sutherland observations
- 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 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)
- Fermi GBM Observations of Magnetar 4U 0142+61
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- GRB 150222A: Further GROND Observations
- GRB 150220A: Fermi GBM observation
- IPN Triangulation of GRB 150220A
- GRB 150222A: I-band observations from OSN
- GRB 150222A: Swift/UVOT Upper Limits
- GRB 150222A: Swift-XRT refined Analysis
- Fermi GBM Observations of SGR 1935+2154
- GRB 150222A: GROND optical afterglow candidate
- Fermi GBM trigger 150223068 is not a GRB
- GRB 150222A: Swift-BAT refined analysis
- SGR 1935+2154: Swift-BAT refined analysis
- GRB 150222A: Mondy optical observations
- GRB 150222A: Zadko observatory - Gingin optical observations
- GRB 150222A: MASTER early optical observations
- GRB 150222A: Swift detection of a burst
- Swift detection of an outburst from SGR 1935+2154
- Trigger 631946: Swift detection of H1745-203
- Fermi GBM trigger 150220229 is not a GRB