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.
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"7444 results found.
- 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
- GRB 130408A: Liverpool Telescope Optical candidate detection
- GRB 130407A Tiled Swift observations
- GRB 130211A: Retraction of afterglow candidate
- GRB 130310A: RATIR Observations
- Swift Trigger 552142: a possible GRB
- GRB 130325A Tiled Swift observations
- GRB 130327A: PAIRITEL NIR Afterglow Candidate
- GRB 130327A: Swift detection of a burst
- GRB 130315A: GROND afterglow candidate
- GRB130313A: GTC early optical limits
- GRB 130315A: Swift detection of a burst
- GRB 130313A: Swift detection of a short burst
- Swift XRT RETRACTION of GRB 130310A afterglow detection
- GRB 130215A: Redshift estimate
- GRB 130215: ROTSE-III Detection of Optical Counterpart
- GRB 130211A: Swift detection of a burst
- GRB 130131A: RATIR optical and infrared upper limits
- GRB 130131B: Swift detection of a burst
- GRB 130131A - UKIRT afterglow candidate
- GRB 130131A: Swift detection of a burst
- GRB 130122A: T100 observations
- GRB 130122A: Swift detection of a burst with an optical counterpart
- GRB 130102A: Swift detection of a burst
- GRB 121229A: Swift detection of a burst
- GRB 121226A: Swift detection of a burst
- GRB 121217A: Swift detection of a burst
- GRB 121212A: Swift detection of a burst
- GRB 121211A - Faulkes Telescope North afterglow confirmation
- GRB 121211A: Swift detection of a burst with an optical counterpart
- GRB 121209A: Keck observations
- GRB 121209A: CARMA 3mm Observations
- GRB 121209A: GROND optical afterglow candidate
- GRB 121209A: UVOT Observation
- GRB 121128A: Optical Observations
- GRB121202A: Swift/UVOT Observations
- GRB 121201A: a GRB with an optical counterpart
- GRB 121128A: FTN optical afterglow confirmation
- GRB 121128A: Swift detection of a burst with an optical counterpart
- GRB 121125A: Fermi GBM Observation
- GRB 121125A: LOAO Observation
- GRB 121125A: Swift detection of a burst with optical counterpart
- GRB 121123A: Fermi GBM observation
- GRB 121123A: Swift detection of a burst with optical counterpart
- GRB 121117A: GROND confirmation of the UVOT afterglow candidate
- GRB 121108A: Swift detection of a burst
- GRB 121102A: Swift detection of a burst
- GRB 121027A: Brightening IR counterpart
- GRB 121028A: Swift detection of a burst
- GRB 121027A: nIR afterglow candidate with AAT
- GRB 121027A: Swift detection of a burst
- GRB 121024A: optical observations
- GRB 121024A: TAROT Calern observatory optical detection of a bright counterpart
- GRB 121024A: Swift detection of a burst with an optical counterpart
- Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
- GRB 121017A: Swift detection of a burst
- GRB 121011A: optical observations
- GRB 121011A: Swift detection of a burst with optical afterglow
- Trigger 535747: Swift detection of an outburst from SGR1806-20
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
- Swift Trigger 535026: Galactic Transient or possible GRB
- GRB 120927A: Swift detection of a burst
- GRB 120922A: Swift/UVOT Observations
- GRB 120923A: Gemini afterglow detection, high-z candidate
- GRB 120922A: TAROT La Silla observatory optical observations
- GRB 120923A: Swift detection of a burst
- GRB 120922A: GROND afterglow candidate
- GRB 120922A: Swift detection of a burst
- Swift Trigger 534017 is probably not real.
- Swift Trigger 533836 is a new Galactic transient
- GRB 120913B: TAROT La Silla observatory optical detection
- GRB 120907A: ROTSE-III Optical Limits
- GRB 120907A: Swift detection of a burst with optical counterpart
- GRB 120821A: Swift/XRT observations
- GRB 120819A: GROND afterglow confirmation
- GRB 120819A: afterglow candidate from NOT
- GRB 120819A: Swift detection of a burst
- GRB 120816A: optical upper limit