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"19533 results found.
- GRB 120521C: Swift/UVOT Upper Limits
- GRB 120521B: Swift/UVOT Upper Limits
- GRB 120521C: MASTER optical limit
- GRB 120521B: GROND Upper limits
- GRB 120521A: XRT light curve (Correction to GCN 13326)
- GRB 120521A: Swift-XRT refined Analysis
- GRB 120521C: PAIRITEL NIR Upper Limits
- GRB 120521C: Enhanced Swift-XRT position
- GRB120521C: Liverpool Telescope observations
- GRB 120521C: TAROT Calern observatory optical observations
- GRB 120521C: Swift detection of a burst
- GRB 120521B: Swift-BAT refined analysis
- GRB 120521B: Swift-XRT refined Analysis
- Swift starts a new program to find fainter transients
- IPN Triangulation of GRB 120519A (short/hard)
- GRB 120521A: Swift/UVOT Upper Limits
- GRB 120521B: Enhanced Swift-XRT position
- GRB 120521A: Swift-BAT refined analysis
- GRB 120521B/Fermi Trigger 359284074: early MASTER-ICATE optical limit
- GRB120521B: Faulkes Telescope South observations
- GRB 120521B: TAROT La Silla observatory optical observations
- GRB 120521B: Swift detection of a burst
- GRB 120521A: Enhanced Swift-XRT position
- GRB 120521A: TAROT La Silla observatory optical observations
- GRB 120521A: Swift detection of a short burst
- GRB 120514A : Suzaku WAM observation of the prompt emission
- Swift Trigger 522245 is a noise fluctuation near IGR J17091-3624
- GRB 120514A: Swift/UVOT Upper Limits
- GRB 120514A: Swift-XRT refined Analysis
- GRB 120514A: Enhanced Swift-XRT position
- GRB 120514A: Swift-BAT refined analysis
- GRB 120514A: TAROT Calern observatory optical observations
- GRB 120514A: Swift detection of a burst
- GRB 120510A: Swift XRT and UVOT observations
- Fermi/GBM detection of a burst from the magnetar 1E 2259+5
- Swift detection of 4U 1630-47
- IPN Triangulation of bright GRB 120426A
- Swift Trigger 520928 is a noise event
- Swift Trigger 520928 is probably not a burst
- GRB 120422A: RAPTOR Limits During Gamma-ray Emitting Interval
- GRB 120422A GROND observations
- GRB 120422A: EVLA Detection
- GRB 120422A: Gemini redshift of candidate host
- GRB 120422A: Zadko observatory - Gingin optical observations
- GRB 120422A: Swift-XRT refined Analysis
- GRB 120422A: A Swift/UVOT Detection
- GRB 120422A: Enhanced Swift-XRT position
- GRB 120422A: Swift-BAT refined analysis
- GRB 120422A: Swift detection of a burst
- GRB 120419A: Swift-XRT and UVOT observations
- Swift Trigger 519874 is a noise event
- SGR1806-20, Swift-BAT refined analysis (Trigger 519868)
- Swift Trigger 519874 is probably a noise event
- Trigger 519868: Swift detection of SGR1806-20
- GRB 120404A: optical observations in Mondy observatory
- GRB 120404A: optical observations
- GRB 120404A, Optical Observations
- GRB 120404A: EVLA Detection
- GRB120404A: GROND observations show steeply decaying afterglow
- GRB120404A: MOA optical observations of the initial rise afterglow
- GRB 120404A: VLT/X-shooter redshift confirmation
- GRB 120404A: Swift/UVOT Detection
- GRB 120403B: Swift-XRT refined Analysis
- GRB 120404A: Swift-XRT refined Analysis
- GRB 120404A: Swift-BAT refined analysis
- GRB 120401A: GROND Detection of an optical/NIR afterglow candidate
- GRB 120404A: Enhanced Swift-XRT position
- GRB 120403B: TAROT La Silla observatory optical observations
- GRB 120403B: Fermi GBM Observation
- GRB 120404A: MASTER early OT limit
- GRB 120404A: Faulkes Telescope North afterglow confirmation
- GRB 120404A: Swift detection of a burst with an optical counterpart
- GRB 120403B: Swift-BAT refined analysis
- GRB 120403B: Swift/UVOT Upper Limits
- GRB 120403B: Enhanced Swift-XRT position
- GRB 120403A: Swift/BAT spectral lag analysis
- GRB 120403B: Swift detection of a burst
- BAT trigger 519207 was a burst from Cyg X-1, was not GRB 120402A
- GRB 120402A: optical upper limit
- GRB 120320A: optical upper limit in Mondy observatory
- GRB 120320A: early optical upper limit
- GRB 120403A: MASTER follow up observations
- GRB 120402A: MASTER follow up observations
- GRB 120403A, Swift-BAT refined analysis
- GRB 120326A: Bassano Bresciano Observatory - correction for GCN Cir 13178
- GRB 120403A: Swift detection of a burst
- GRB 120402A: Swift detection of a possible burst or noise
- GRB 120326A: Cima Rest and Bassano Brescia
- GRB 120401A: Swift-XRT refined Analysis
- GRB 120401A: Swift-BAT refined analysis
- GRB 120401A: Enhanced Swift-XRT position
- GRB 120401A: Prompt enhanced Swift-XRT position
- GRB 120401A: Swift detection of a burst
- GRB 120326A: EVLA Observations
- GRB 120324A: CrAO optical upper limit
- GRB 120326A: Bassano Bresciano Observatory lightcurve analisis
- GRB 120326A : Suzaku WAM observation of the prompt emission
- Swift trigger 518853 is most likely GX 301-2
- GRB 120326A: Bassano Bresciano Observatory optical observations
- Swift trigger 518853: MASTER-ICATE possible OT