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"19089 results found.
- GRB 150314A: Early RAPTOR Detection
- GRB 150314A: NOT further optical observations
- GRB 150314A: NOT optical observations
- GRB 150314A: Swift/UVOT Detection
- GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
- GRB 150314A: Enhanced Swift-XRT position
- GRB 150314A: Swift detection of a bright burst
- GRB 150309A: AAO optic upper limit
- GRB 150222A: CrAO optical observation
- GRB 150309A: CrAO optic upper limit
- GRB 150309A: ISON-Kislovodsk optic upper limit
- GRB 150309A: Swift-BAT refined analysis
- GRB150309A: Optical observations at Crni Vrh
- GRB 150309A: Swift/UVOT Upper Limits
- GRB 150309A: Swift-XRT refined Analysis
- GRB 150309A: Enhanced Swift-XRT position
- GRB 150309A: Swift detection of a burst
- Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
- 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)
- 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: Mondy optical upper limit
- GRB 150302A: Swift/UVOT Upper Limits
- GRB 150302A: MITSuME Okayama upper limits
- GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
- GRB 150302A: Enhanced Swift-XRT position
- GRB 150220A: further Swift-XRT observations
- GRB 150301B: Swift/UVOT Observations
- GRB 150302A: UVOT Observations
- GRB 150302A: NOT afterglow candidate
- GRB 150302A: Swift detection of a burst
- GRB 150301B: GROND afterglow observations
- GRB 150301A: Swift/UVOT Upper Limits
- GRB 150301B: Enhanced Swift-XRT position
- GRB 150301A: Swift-BAT 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: Swift detection of a short burst or new SGR
- 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: Swift ToO observations
- GRB 150222A: I-band observations from OSN
- GRB 150222A: Swift/UVOT Upper Limits
- Fermi GBM Observations of SGR 1935+2154
- GRB 150222A: GROND optical afterglow candidate
- GRB 150222A: Enhanced Swift-XRT position
- GRB 150222A: TNG optical observations
- SGR 1935+2154: Swift-BAT refined analysis
- GRB 150222A: Mondy optical observations
- GRB 150222A: Zadko observatory - Gingin optical observations
- GRB 150222A: Swift detection of a burst
- Swift detection of an outburst from SGR 1935+2154
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150213B: AAO photometry
- GRB 150219A: Swift ToO observations
- GRB 150213B: Enhanced Swift-XRT position
- GRB 150213B: Swift/UVOT Detection
- GRB 150213B: RATIR Optical and NIR Observations
- GRB 150213B: AAO optical observations
- GRB 150213B: optical detection from the NOT
- GRB 150212A: Swift/UVOT Observations
- GRB 150213B: Swift detection of a burst with an optical afterglow
- GRB 150212A: RATIR Optical and NIR Observations
- GRB 150212A: Khureltogot optical upper limit
- GRB 150212A: Skynet DSO14/GORT observations
- GRB 150212A: No Swift/UVOT detection in initial observation
- GRB 150212A: P60 Afterglow Retraction
- GRB 150210A: Swift-XRT observations
- GRB 150212A: Swift-XRT afterglow detection
- GRB150212A: P60 Afterglow Candidate
- GRB 150211A iTelescope observation
- GRB 150211A: Swift/UVOT Upper Limits
- GRB 150211A: Mondy optical upper limit
- GRB 150210A: Tiled Swift observations
- GRB 150210A: Fermi-LAT detection
- GRB 150211A: RATIR Optical and NIR Observations
- GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
- GRB 150211A: Swift-XRT observations
- GRB 150204A: GROND observations
- GRB 150203A iTelescope observation
- GRB 150206A: Swift/UVOT Detection
- GRB 150206A: Swift-XRT refined Analysis
- GRB 150206A: GROND afterglow observations
- GRB 150206A: Enhanced Swift-XRT position
- Trigger 630047: Swift detection of 1RXS J180408.9-342058
- GRB 150206A: Swift detection of a burst with an optical afterglow
- GRB 150204A: Swift/UVOT Upper Limits
- GRB 150204A: Swift ToO observations
- Swift Trigger 629693 was a noise event
- GRB 150203A: RAPTOR Limits Beginning at the Gamma-Ray Emitting Interval
- GRB 150203A: Swift/UVOT Upper Limits
- GRB 150203A: ISON-NM early optical limit
- IPN Triangulation of GRB 150202B
- GRB 150203A: Swift-XRT refined Analysis