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"2908 results found.
- GRB 130831A: Maidanak optical observations
- GRB 130831A: ISON-Kislovodsk optical observations
- GRB 130831A: optical observation in Gissar AO
- GRB 130903A: Fermi GBM observation
- GRB 130903A: A long GRB detected by INTEGRAL
- Konus-Wind observation of GRB 130821A
- GRB 130816A: REM NIR candidate afterglow
- Refined IPN Triangulation of GRB 130812B
- GRB 130725B: GROND Detection of the Optical/NIR Afterglow
- GRB 130719A: Swift detection of a burst
- Fermi GBM trigger 394325281 / 130630950 is not a GRB
- GRB 130627B: Swift detection of a burst
- Swift Trigger 558828 is not an interesting event
- GRB 130615A: Swift detection of a burst
- Swift Trigger 557674 was due to an onboard position error
- GRB 130606A, Swift-BAT refined analysis
- GRB 130606A: EVLA detection
- GRB 130606A: Skynet/PROMPT detection of the optical afterglow
- GRB 130606A: Enhanced Swift-XRT position
- GRB 130606A: AAO optical observations
- GRB130606A: Montarrenti Observatory afterglow detection
- Virtual Telescope observations of GRB 130606A
- GRB 130606A: IRSF NIR Observation
- GRB 130606A: NOT afterglow detection
- GRB 130606A: Swift detection of a burst
- GRB 130605A: GROND afterglow candidate
- Swift Trigger 557466 is probably not real.
- GRB 130603A: Swift-XRT and Swift-UVOT detections
- GRB 130511A: Swift detection of a burst with an optical counterpart
- GRB 130504C: Fermi GBM detection
- GRB 130502A: Swift-BAT refined analysis
- GRB 130502B: Fermi GBM detection of a burst
- GRB 130427A: high energy gamma-ray detection by AGILE
- GRB 130427B: MITSuME Ishigakijima upper limits
- GRB 130427A optical time series
- Konus-Wind observation of GRB 130427A
- GRB 130427A: SPI-ACS/INTEGRAL observations
- GRB 130427B: MITSuME Okayama upper limits
- GRB 130427A: RAPTOR Bright Counterpart Before Swift Trigger
- GRB 130427A: Fermi GBM observation
- GRB 130427A: Fermi-LAT detection of a burst
- GRB 130427A: Swift-BAT refined analysis
- GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
- GRB 130420B: CARMA and VLA radio observations
- GRB 130418A: Swift detection of a burst with an optical counterpart
- GRB 130211A: Retraction of afterglow candidate
- Konus-Wind observation of GRB 130320B
- GRB 130327B: Fermi GBM detection
- GRB 130327A: Swift detection of a burst
- GRB 130315A: GROND afterglow candidate
- GRB 130305A: optical upper limit in Mondy observatory
- GRB 130313A: optical upper limit in Mondy observatory
- GRB 130315A: Swift-XRT refined Analysis
- GRB 130315A, Swift-BAT refined analysis
- GRB 130315A: Swift detection of a burst
- Konus-Wind observation of GRB 130306A
- GRB 130306A: Fermi GBM observation
- GRB 130305A: P60 Observations
- GRB 121128A: optical observations in Mondy observatory
- GRB 121128A: optical upper limit in Maidanak observatory
- GRB 130206A: GROND Observations
- GRB 130131A: Swift-BAT refined analysis
- GRB 130122A: optical observations
- GRB 121229A: MAXI/GSC detection
- GRB 121217A: Swift detection of a burst
- GRB 121211A: Fermi GBM observation
- GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
- GRB 121211A: Swift detection of a burst with an optical counterpart
- GRB 121209A: GROND optical afterglow candidate
- IPN Triangulation of GRB 121118B (long/intense)
- GRB 121117A: MASTER prompt optical limit
- GRB 121108A: Swift-XRT refined Analysis
- GRB 121108A: Xinglong TNT upper limit
- GRB 121108A: Swift detection of a burst
- GRB 121031A: Fermi GBM detection
- GRB 121024A: MITSuME Ishigakijima upper limits
- IPN Triangulation of short hard GRB 121011B
- GRB 120913B: REM NIR early time detection
- GRB 120908A: MAXI/GSC detection
- GRB 120830A: early MASTER optical limit
- IPN Triangulation of short GRB 120830A
- Fermi trigger 368003226 : MASTER optical observations
- GRB 120821A: GROND upper limits
- Swift Trigger 530581: GRB 120811A or a galactic transient
- GRB120805A: Liverpool Telescope observations
- GRB 120804A: Gemini-North observations
- GRB 120802A: Swift detection of a burst
- Trigger 529076: Swift possible detection of SwJ1910.2-0546
- GRB 120716A: Swift/XRT position consistent with that of the optical counterpart
- Swift trigger 524642 / SwJ1910.2-0546
- Swift Trigger 524642 is Swift J1910.2-0546
- GRB 120528B: MAXI/GSC detection
- GRB 120521C - NOT optical limits
- GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate
- GRB 120510A: MAXI/GSC detection of a burst
- IPN Triangulation of GRB 120427A
- Swift detection of 4U 1630-47
- GRB 120424A: MAXI/GSC detection of a burst
- GRB 120404A: optical observations in Mondy observatory
- GRB 120403B: Swift-BAT refined analysis