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"27047 results found.
- GRB 130131A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 130131B: Swift-XRT refined Analysis
- GRB 130131B: GROND Upper limits
- GRB 130131B: Swift/UVOT Upper Limits
- GRB 130131A: Swift-XRT refined Analysis
- GRB 130131B: Swift-BAT refined analysis
- GRB 130131A: Swift-BAT refined analysis
- GRB 130131B: TAROT Calern observatory optical observations
- GRB 130131B: Zadko observatory - Gingin optical observations
- GRB 130131B: Swift detection of a burst
- GRB 130131A - Faulkes Telescope North Observations
- GRB 130131A - UKIRT afterglow candidate
- GRB 130131A: Swift detection of a burst
- Swift/BAT trigger 547142 is new source Swift J1753.7-2544
- GRB 130127A: Fermi GBM detection
- Swift Trigger 547142: MAXI/GSC upper limit
- Swift Trigger 547142: a probable Galactic source
- GRB 130122A: Swift/UVOT Detection
- GRB 130122A: RATIR Detection
- GRB 130122A: Swift-BAT refined analysis
- GRB 130122A: Swift-XRT refined Analysis
- GRB 130122A: Xinglong optical upper limit
- GRB 130122A: T100 observations
- GRB 130122A: Swift detection of a burst with an optical counterpart
- GRB 121225B: Suzaku WAM observation of the prompt emission
- GRB 130102B: MASTER synchronous observations
- GRB 130102A: Swift/UVOT Upper Limits
- GRB 130102A: P60 Observations
- GRB 130102A: Swift-BAT refined analysis
- GRB 130102A: Swift-XRT refined Analysis
- GRB 130102A: Swift detection of a burst
- Swift Trigger 544381 is a noise event
- GRB 121229A: Swift-XRT refined Analysis
- GRB 121229A, Swift-BAT refined analysis
- GRB 121229A: Swift/UVOT Upper Limits
- GRB 121229A: VLT/X-shooter redshift
- Swift Trigger 544381 is unlikely to be a GRB
- GRB 121229A: MAXI/GSC detection
- GRB 121229A: GROND detection of the afterglow
- GRB 121229A: Swift detection of a burst
- GRB 121226A: Swift/UVOT Upper Limits
- GRB 121226A: Swift-XRT refined Analysis
- GRB 121226A, Swift-BAT refined analysis
- GRB 121226A: NOT optical upper limit
- GRB 121226A: Optical Observations
- GRB 121226A: Zadko observatory - Gingin optical observations
- GRB 121226A: BOOTES-4/MET optical observations
- GRB 121226A: Swift detection of a burst
- IPN Triangulation of GRB 121225B
- GRB 121225B: Fermi GBM observation
- GRB 121225B: Fermi LAT Detection
- Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
- Trigger 543763: SGR 1E 1841-045: Swift detection of a soft gamma repeater burst (aka Kes 73)
- GRB 121217A: Swift-BAT refined analysis
- GRB 121217A theoretical estimate of redshift and of supernova occurrence
- GRB 121217A: Fermi GBM observation
- GRB 121217A: Swift-XRT refined Analysis
- GRB 121217A: Swift/UVOT Detection
- GRB 121217A: GROND Detection of the Afterglow
- GRB 121217A: Swift detection of a burst
- GRB 121209A: Swift/UVOT Upper Limits
- GRB 121212A: LOAO IzY Observation
- GRB 121209A: MAXI/GSC detection
- GRB121212A: NOT optical imaging
- GRB 121209A: Early CARMA Observations
- GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
- GRB 121211A: Fermi GBM observation
- GRB 121211A: RATIR Optical and NIR Observations
- GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 121212A: PAIRITEL NIR Observations
- GRB 121212A: Swift-XRT refined Analysis
- GRB 121212A: P60 Observations
- GRB 121212A: optical observations in ISON-NM observatory
- GRB121212A: Swift/UVOT Detection
- GRB 121212A: Swift-BAT refined analysis
- GRB 121211A: Swift-BAT refined analysis
- GRB 121212A: Swift detection of a burst
- GRB 121211A: Swift/UVOT Detection
- GRB 121211A: Swift-XRT refined Analysis
- GRB 121211A: Keck/LRIS redshift
- GRB 121211A - Faulkes Telescope North afterglow confirmation
- GRB 121211A: Swift detection of a burst with an optical counterpart
- GRB 121209A: Swift-XRT refined Analysis
- GRB 121209A: Swift-BAT refined analysis
- GRB121209A: RATIR Optical and NIR Upper Limits
- GRB 121209A: GROND optical afterglow candidate
- GRB 121209A: Gemini-South imaging
- GRB 121209A: PAIRITEL NIR Observations
- GRB 121209A: UVOT Observation
- GRB 121209A: Swift detection of a burst
- GRB 121127A: Suzaku WAM observation of the prompt emission
- GRB 121128A: Optical Observations
- GRB 121122A: Suzaku WAM observation of the prompt emission
- GRB 121202A: Swift/UVOT Upper Limits
- GRB 121202A: Swift-XRT refined Analysis
- GRB 121202A: Fermi GBM observation
- GRB 121202A: Swift-BAT refined analysis
- GRB 121202A: Swift-XRT observations
- GRB121202A: Swift/UVOT Observations