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"8296 results found.
- GRB 140413A: TAROT La Silla observatory optical observations
- GRB 140413A: GROND afterglow candidate
- GRB 140412A: Swift detection of a burst
- GRB 140408A: 1.5m OSN optical upper limit
- Swift Trigger 595345 is not an astrophysical source
- Fermi418277210: iPTF optical observations
- GRB 140408A: RATIR Optical Upper Limits
- GRB 140408A: GROND Detection of an Afterglow Candidate
- GRB 140408A: Swift detection of a burst
- Swift trigger 594286: Is likely a noise trigger
- GRB 140302A: TAROT La Silla observatory optical observations
- GRB 140323A: Zadko observatory - Gingin optical observations
- GRB 140331A: Swift detection of a burst
- GRB 140320D: MASTER optical observations
- GRB 140320C: Mondy optical observations and afterglow confirmation
- GRB 140323A: Swift detection of a burst
- GRB 140320B: P60 detection of a very red afterglow
- GRB 140320A: Swift-XRT detection of an afterglow candidate
- GRB 140320C: FTN optical observations
- GRB 140320B: FTN optical afterglow candidate
- GRB 140320A: Fermi GBM observations suggest a short GRB
- GRB 140318A: Swift detection of a burst
- GRB 140311C: Fermi GBM Detection
- Fermi416242156: possible iPTF counterpart
- GRB 140311A: Nanshan afterglow decay
- GRB 140305A: Swift-BAT refined analysis
- GRB 140304A: Swift detection of a burst
- GRB 140302A: GROND afterglow candidate
- GRB 140302A: Swift detection of a burst
- GRB 140301A: NOT afterglow candidate
- GRB 140301A: Swift detection of a burst
- GRB 140226A/iPTF14yb: RATIR Optical and NIR Observations
- GRB 140219A: Mondy optical observations of XRT source #5
- PTF14yb: GROND Transient Detection
- iPTF14yb: iPTF Discovery of an Optical Afterglow-like Transient
- GRB 140219A: Retraction of X-ray afterglow
- GRB 140219A: iPTF optical observations
- GRB 140219A: optical observations of XRT source #5
- GRB 140219A: XRT afterglow candidate
- GRB 140219A: Xuyi and Nanshan upper limits
- GRB 140221A Tiled Swift observations
- GRB 140219A Tiled Swift observations
- GRB 140215A: WSRT radio observation
- GRB 140215A: Swift detection of a burst with optical counterpart
- GRB 140213A: Swift/UVOT Detection
- GRB 140209A: Swift-BAT Spectral lag analysis
- GRB 140209A, Swift-BAT refined analysis
- GRB 140206A: Swift/UVOT optical detection
- GRB140206A - Optical afterglow candidate
- GRB 140129B: MASTER OT early light curve
- GRB 140129B: Swift detection of a burst with an optical afterglow
- GRB 140129A: ROTSE-III Detection of Optical Counterpart
- GRB 140129A: Swift detection of a burst with an optical afterglow
- Fermi412093190: iPTF optical counterpart search
- GRB 140103A: MASTER-Net early OT detection
- GRB 140103A: optical upper limit
- GRB 140103A: AAO optical afterglow candidate
- GRB 140114A: Swift detection of a burst
- GRB 140110A: Swift/UVOT retraction of UVOT candidates
- GRB 140110A Tiled Swift observations
- GRB 140108A: D50+BART optical candidate detection
- GRB 140108A: 1.23m CAHA observations
- GRB 140108A: MASTER-Net OT detection
- GRB 140108A: Swift detection of a burst
- New Fermi-LAT GRB Table
- GRB 140105A/Fermi410578384: MASTER-Net early optical observations
- Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
- GRB 140102A, Optical Observations
- GRB 140102A: Fermi-LAT detection of a burst
- GRB 140103A: Swift detection of a burst
- GRB 140102A: Swift detection of a burst with optical counterpart
- GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
- GRB 131231A: afterglow confirmation from the NOT
- GRB 131231A: Nanshan afterglow candidate
- GRB 131229A: Swift detection of a burst
- GRB 131227A: OT candidate from KAIT Optical observations
- GRB 131227A: Swift detection of a burst
- GRB 131216A: Suzaku WAM observation of the prompt emission
- GRB 131218A: Zadko observatory - Gingin optical candidate
- Trigger 581129: Swift-BAT triggered on noise
- GRB 131209A: Swift XRT and UVOT observations
- GRB 131209A Tiled Swift observations
- GRB 131205A: Swift detection of a burst
- GRB 131126A: iPTF upper limits on the afterglow of a short GRB
- GRB 131202A: Swift detection of a burst
- GRB 131127B: Bassano Bresciano Observatory optical observations of iPTF13ecv
- GRB 131127A: RATIR Rejection of High-z Candidate
- GRB 131128A: Swift/UVOT Detection
- GRB 131127B: Bassano Bresciano Observatory optical observations
- GRB 131128A: Nanshan afterglow confirmation
- GRB 131128A: MASTER-Net optical observations
- GRB 131128A: Nanshan afterglow candidate
- GRB 131128A: Swift detection of a burst
- GRB 131127A: RATIR Optical and NIR Observations, High-z Candidate
- Fermi407254341: iPTF optical afterglow candidates
- GRB 131127A: Swift detection of a burst
- GRB 131117A: Swift detection of a burst
- GRB 131108A: Fermi GBM observation
- GRB 131108A: Fermi-LAT refined analysis
- GRB 131108A: 1.23m CAHA optical candidate