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"7422 results found.
- 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
- GRB 130816B: Swift detection of a burst
- GRB 130816A: REM NIR candidate afterglow
- GRB 130816A: Swift detection of a burst
- GRB 130812A: Swift detection of a burst
- GRB 130807A: Swift detection of a GRB or Galactic transient
- GRB 130806A: Swift detection of a burst
- Trigger 565443: Swift detection of a burst from SGR J1745-29
- GRB 130803A: Faulkes Telescope South Observations
- GRB 130803A: Swift detection of a burst
- GRB 130722A: RATIR Optical Observations
- GRB 130727A: Swift-XRT and Swift-UVOT prompt observations
- GRB 130725A: MITSuME Ishigakijima Optical Observation
- GRB 130719A: Skynet/PROMPT observations
- Swift Trigger 563980 is GRB 130725A
- GRB 130722C Tiled Swift observations
- GRB 130722A: Faulkes Telescope South optical candidate
- GRB 130722A: Swift detection of a burst
- GRB130702A: Redshift of Afterglow Candidate iPTF13bxl
- GRB 130701A: Swift detection of a burst
- GRB 130626A: KAIT Optical Observations
- GRB 130626A: RATIR Optical Observations
- GRB130627B: Swift/UVOT Observations
- GRB 130626A: Swift-XRT possible detection and UVOT upper limits
- GRB 130627A: Swift/UVOT Observation
- GRB 130626A: Swift detection of a short burst
- GRB 130625A: Swift detection of a burst
- Swift Trigger 558631 is not a real source
- GRB 130615A: Zadko observatory - Gingin optical observations
- GRB 130615A: TAROT La Silla observatory optical observations
- GRB 130615A: GROND afterglow candidate
- GRB 130615A: Swift detection of a burst
- GRB 130612A: Liverpool Telescope Afterglow detection
- GRB 130612A: Swift detection of a burst with an optical counterpart
- GRB 130606B: Swift/UVOT Upper Limit
- GRB 130610A - Liverpool Telescope Optical Afterglow Confirmation
- GRB 130610A: Swift detection of a burst with an optical counterpart
- GRB 130609B: Swift detection of a burst with an optical counterpart
- GRB 130609A: Swift detection of a burst
- GRB 130608A: Swift detection of a burst
- GRB 130606A: Swift detection of a burst
- GRB 130605A: GROND afterglow candidate
- GRB 130605A: Swift detection of a burst
- Swift Trigger 557466 is probably not real.
- GRB 130604A: further ISON-NM optical observation
- GRB 130604A: ISON-NM optical upper limit
- GRB 130604A: P60 optical afterglow candidate
- GRB 130603B: WHT optical afterglow candidate
- GRB 130603B: Swift detection of a bright short burst
- GRB 130529A: Swift detection of a burst
- GRB 130528A: Swift detection of a burst
- GRB 130527A: Swift detection of a bright burst
- Swift Trigger 556533 is probably not an astrophysical event
- GRB 130515A: FORS2 spectroscopy of candidate counterpart
- GRB 130515A: Swift detection of a short burst
- GRB 130514A: Swift detection of a burst
- GRB 130511A: Swift detection of a burst with an optical counterpart
- GRB 130508A: Swift detection of a probable burst
- GRB 130505B: Swift Candidate Afterglow
- GRB 130504A: IAC80 optical candidate
- GRB 130505A: Swift detection of a burst with optical afterglow
- GRB 130504A: Bassano Bresciano Observatory optical upper limit
- GRB 130504A, Swift-BAT refined analysis
- Swift-XRT X-ray afterglow candidate for GRB 130504A (BAT trigger 555096)
- Trigger 555096: Swift detection of a possible burst
- GRB 130502A: Swift/UVOT Upper Limits
- GRB 130502B: P60 Observations
- GRB 130502A: TNG candidate counterpart
- GRB 130502A: Swift detection of a burst
- GRB 130427B: Swift detection of a burst with optical counterpart
- Swift Trigger 554135 is probably not a GRB or transient
- GRB 130420B: Swift detection of a burst
- GRB 130420A: ROTSE-III Detection of Optical Counterpart
- GRB 130420A: Swift detection of a burst with an optical counterpart
- GRB 130420A: Faulkes Telescope North candidate
- GRB 130418A: Bassano Bresciano Observatory optical observations
- GRB 130418A: Swift detection of a burst with an optical counterpart
- GRB 130408A: Swift/UVOT Detection of the Optical Afterglow