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"27019 results found.
- Swift Trigger 524949: Noise fluctuation near a galaxy
- Swift trigger 524642 / SwJ1910.2-0546
- GRB 120602A: Suzaku WAM observation of the prompt emission
- Swift Trigger 524642 is Swift J1910.2-0546
- Trigger 524584: Swift detection of Algol
- Swift triggers (#524542) on a Galactic source
- GRB 120612A: Swift/UVOT observations
- GRB 120612A: Swift-XRT refined Analysis
- GRB 120612A: Swift-BAT refined analysis
- GRB 120612A: Swift detection of a burst
- GRB 120603A: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 120603A
- IPN Triangulation of short GRB 120603A
- Fermi GBM trigger 120602.539 is not a GRB
- GRB 120519A: Suzaku WAM observation of the prompt emission
- Fermi Gamma-ray Burst Monitor trigger 120527.573 is not a GRB
- GRB 120512A: Suzaku WAM observation of the prompt emission
- GRB 120521B: Fermi GBM observation
- GRB 120521C: Early Tautenburg limits
- GRB 120521A: GROND Upper limits
- GRB 120521C: Swift-XRT refined Analysis
- GRB 120521C: Swift-BAT refined analysis
- GRB 120521C: Swift/UVOT Upper Limits
- GRB 120521B: Swift/UVOT Upper Limits
- GRB 120521C: MASTER optical limit
- GRB 120521B: GROND Upper limits
- GRB 120521A: Swift-XRT refined Analysis
- GRB 120521C: PAIRITEL NIR Upper Limits
- GRB 120521C: WHT optical observations
- GRB 120521C - NOT optical limits
- 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 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: 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: GROND upper limits
- GRB 120514A: Swift/UVOT Upper Limits
- GRB 120514A: Swift-XRT refined Analysis
- GRB 120514A: Swift-BAT refined analysis
- GRB 120514A: TAROT Calern observatory optical observations
- GRB 120514A: Swift detection of a burst
- Fermi GBM Trigger 358364818 is not a GRB
- Fermi Trigger 358364818: BOOTES-4 observations
- GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate
- GRB 120510A: Swift XRT and UVOT observations
- Fermi/GBM detection of a burst from the magnetar 1E 2259+5
- GRB 120422A: CARMA 3mm observations
- GRB 120422A: i-band re-brightening and possible SN detection
- IPN Triangulation of GRB 120427A
- 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: JCMT SCUBA-2 sub-mm observation
- GRB 120422A: RAPTOR Limits During Gamma-ray Emitting Interval
- GRB 120422A GROND observations
- GRB 120422A: Super-LOTIS early observations
- GRB 120422A: Zadko observatory - Gingin optical observations
- GRB 120422A: Swift-XRT refined Analysis
- GRB 120422A: A Swift/UVOT Detection
- GRB 120422A: Swift-BAT refined analysis
- GRB 120422A: Gemini observations
- GRB 120422A: Faulkes Telescope North observations
- 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
- GRB 120404A, Optical Observations
- GRB 120404A: JCMT SCUBA-2 sub-mm observation
- GRB 120404A: MASTER OT observations
- 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 120403B: TAROT La Silla observatory optical observations
- GRB 120403B: Fermi GBM Observation
- GRB 120404A: Gemini-N Redshift
- GRB 120403B: AAT nIR observations
- GRB 120404A: MITSuME Akeno Optical upper limits
- GRB 120404A: Faulkes Telescope North afterglow confirmation
- GRB 120404A: Swift detection of a burst with an optical counterpart