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"4613 results found.
- GRB 120422A: CARMA 3mm observations
- Swift detection of 4U 1630-47
- GRB 120424A: MAXI/GSC detection of a burst
- SGR1806-20, Swift-BAT refined analysis (Trigger 519868)
- Trigger 519868: Swift detection of SGR1806-20
- GRB 120404A: MASTER OT observations
- GRB 120404A: MASTER early OT limit
- GRB 120402B: Fermi GBM detection
- GRB 120401A: Swift detection of a burst
- GRB120327A - ATCA radio afterglow detection at 34GHz
- GRB 120324A: CrAO optical upper limit
- GRB 120324A, the review of the sky area in plate archives
- Trigger 518853: Swift detection of a probable Galactic transient
- IPN Triangulation of GRB 120328B (long/intense)
- GRB 120328A: Swift detection of a burst
- GRB 120327A: Swift/UVOT further analysis
- GRB 120327A: Swift-BAT refined analysis
- GRB 120327A: Enhanced Swift-XRT position
- GRB 120327A: Liverpool Telescope Observations
- GRB 120327A: Swift detection of a burst with an optical counterpart
- GRB 120326A: T17 optical observations
- GRB 120324A: CQUEAN rizY Observation
- GRB 120324A: Liverpool Telescope optical candidate
- Simultaneous optical images of Swift pointing are available by GRT
- GRB 120316A : Suzaku WAM observation of the prompt emission
- GRB 120312A, the review of the sky area in plate archives
- GRB 120312A: WHT candidate afterglow
- GRB 120311B: C88 optical limits
- GRB 120312A: Swift detection of a burst
- GRB 120224A: optical observation in Mondy observatory
- GRB 120224A: FTN optical observations
- Fermi GBM detection of an SGR-like burst
- Skynet/PROMPT observations of GRB120215A
- GRB 120213A: Enhanced Swift-XRT position
- GRB 120213A: Swift-BAT refined analysis
- GRB 120213A: Prompt enhanced Swift-XRT position
- GRB 120213A: Swift detection of a burst
- GRB 120212A: NOT optical observation
- GRB 120211A: MASTER early optical observations
- GRB 120211A - Faulkes Telescope South Observations
- Swift detection of a burst from LS I +61 303
- GRB 111225A: optical observations
- GRB 120119A: optical observations
- GRB 120119A: Swift detection of a burst with an optical counterpart
- XRF 120118A: early optical limit by "Pi of the Sky"
- GRB 120118B: MASTER optical observations
- GRB 120118B: Swift detection of a burst
- AXP 4U 1042+61: Mondy optical observations
- GRB 120116A: Mondy optical observations
- AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
- GRB 120106A: optical upper limit
- Swift detection of an SGR burst from AXP 4U 0142+61
- GRB 120107A: Suzaku WAM observation of the prompt emission
- GRB 120106A: Swift detection of a burst
- GRB 120102A: Swift/UVOT Detection
- GRB 120102A: Swift detection of a burst with an optical counterpart
- GRB 111228A: MASTER-Net optical photometry
- GRB111228A: Further GMG observations
- FERMI GRB111228.45: MASTER observations
- GRB111222A: GMG optical observation
- XRT GRB Catalogue now live and online
- GRB 111209A: IRTF NIR Imaging/Spectroscopy
- GRB 111204A, Swift-BAT refined analysis
- GRB 111204A: MASTER optical observations
- GRB 111123A, GROND observations
- GRB 111121A: Swift detection of a short hard burst
- GRB 111117A: optical upper limit in CrAO
- XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
- Continued Skynet observations of GRB111107A
- GRB 111107A: Swift detection of a burst with an optical counterpart
- Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
- GRB 111022B: MASTER OT observations
- IPN Triangulation of GRB 111016B (long duration, intense)
- GRB 111018A: Swift detection of a burst
- Fermi GBM triggers 110923481, 110924391 and 110925200 are not GRBs
- MAXI/GSC detection of a short soft X-ray transient
- GRB 110915B: SuperAGILE localization of a long GRB
- GRB 110731A: SAO RAS and Terskol observations
- IPN triangulation of GRB110825A (very intense, long-duration)
- GRB110820A: MITSuME Ishigakijima Optical Upper Limits
- IPN triangulation of GRB110815A (long, intense)
- IPN triangulation of GRB 110808B (short/hard/intense)
- SGR J1834.9-0846: A Neutron Star in W41?
- Konus-Wind observation of GRB 110802A
- GRB 110801A: SAO RAS optical observations
- GRB 110801A: Evidence for a jet break
- GRB 110801A: MASTER OT observations
- AXP 4U 0142+61: Fermi GBM detection
- AXP 4U 0142+61: Swift-BAT refined analysis
- Swift detection of a SGR-like burst from the AXP 4U 0142+61
- GRB 110709A: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 110709A
- GRB110709A: upper limits from CAHA 1.23m and OSN 1.5m
- GRB 110709A: Fermi GBM observation
- GRB 110709A: Swift detection of a burst
- GRB 110625A: Suzaku WAM observation of the prompt emission
- GRB 110625A: GROND detection of a source inside the XRT error circle
- Konus-Wind observation of GRB 110625A
- GRB 110610A: Swift detection of a burst
- GRB 110530A: optical observations at Mt. Terskol