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"7299 results found.
- GRB 140219A Tiled Swift observations
- GRB 140215A: Swift detection of a burst with optical counterpart
- GRB 140213A: Swift/UVOT Detection
- GRB 140206A: Swift/UVOT optical detection
- GRB140206A - Optical afterglow candidate
- 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: 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
- 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 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 130925A: HST imaging
- GRB 131108A: Fermi GBM observation
- GRB 131108A: Fermi-LAT refined analysis
- GRB 131108A: 1.23m CAHA optical candidate
- GRB 131108A Tiled Swift observations
- GRB 131105A: TAROT La Silla observatory optical observations
- GRB 131105A: VLT/X-shooter optical afterglow candidate
- GRB 131105A: Swift detection of a burst
- GRB 131103A: Swift detection of a burst
- GRB 131031A: Swift/UVOT Upper Limits
- GRB 131031A: 1.23m CAHA afterglow candidate
- GRB 131030A: Swift detection of a burst with an optical counterpart
- GRB 131029A Tiled Swift observations
- Swift Trigger 575905: a possible GRB
- GRB 131024B: Swift detection of a burst
- GRB 131024A: Swift detection of a burst
- GRB 131014A: RATIR Optical/NIR Afterglow Retraction
- GRB 131018B: Swift/UVOT Upper Limits
- GRB 131018A: Swift detection of a burst
- GRB 131014A: Swift/UVOT Upper Limits
- GRB 131014A: RATIR Optical and NIR Observations
- GRB 131014A: NOT afterglow candidate
- GRB 131014A Tiled Swift observations
- GRB 131011A: Fermi GBM detection
- iPTF 13dsw/Fermi403206457: X-Shooter redshift
- Swift-XRT detection of iPTF 13dsw/Fermi403206457
- GRB 131011A: GROND afterglow observations
- Fermi403206457: continued P60 observations and fading behavior
- Fermi403206457: Weihai optical upper limit
- Fermi403206457: NOT optical observations
- Fermi403206457: iPTF detection of a possible optical afterglow
- Trigger 574266 is not a Swift detection of a known source
- GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
- GRB 131004A: TNG optical afterglow confirmation
- GRB 131004A: Swift detection of a burst (may be short)
- GRB 130925A/Sw J0244-2609: mm observations at PdBI
- NuSTAR observations of GRB 130925A
- GRB 131002B: Swift detection of a burst
- GRB 131002A: Swift detection of a burst
- GRB 130929A: Swift detection of a burst
- GRB 130925A: GROND afterglow candidate
- GRB 130925A: Swift detection of a burst
- GRB 130912A: Swift detection of a short burst
- GRB 130907A: Swift detection of a burst with an optical counterpart
- Swift follow-up of an INTEGRAL possible weak GRB
- Swift Trigger 569022: a possible GRB
- GRB 130831B: Swift detection of a burst
- GRB 130831A: Swift detection of a burst with an optical counterpart
- GRB 130828A Tiled Swift observations
- GRB 130822A: Swift detection of a short burst
- GRB 130816B: GROND afterglow candidate