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"40764 results found.
- GRB 140430A: VATT Optical Observations
- GRB 140430A: VLT/X-shooter redshift
- GRB 140430A: NOT optical observations
- GRB 140430A : Liverpool Telescope optical afterglow observations
- GRB 140428A: GROND observations
- GRB140430A: Swift detection of a burst with an optical counterpart
- GRB 140428B: Fermi GBM observation
- Konus-Wind observation of GRB 140428B
- GRB 140428A: Swift/UVOT Upper Limits
- GRB 140428A: Swift-BAT refined analysis
- GRB 140423A: RTT150 optical observations
- IPN Triangulation of GRB 140428B (short/hard)
- Trigger 597570: Swift detection of SGR 1806-20
- GRB 140428A: 1.5m OSN I-band detection
- GRB 140428A: Keck redshift estimate
- GRB 140428A: Keck detection of a red optical afterglow candidate
- GRB 140428A: NOT observations
- GRB 140428A: Swift-XRT detection of a source
- GRB 140428A: Swift Detection of a Possible Burst
- GRB 140423A: MITSuME Akeno upper limits
- GRB 140423A Third epoch pODI photometry
- GRB 140423A: Continued RATIR Optical and NIR Observations
- GRB 140423A: MITSuME Akeno Optical observation
- GRB 140413A: GROND Afterglow Confirmation
- DG CVn: optical observations
- GRB 140423A: RATIR Optical and NIR Observations
- GRB 140423A: NOT Afterglow Observations
- GRB 140419A: Continued Mondy optical observations
- GRB 140423A: Nishi-Harima NIR Observations
- GRB 140423A: TNG NIR observations
- GRB 140423A pODI/WIYN afterglow photometry
- GRB 140423A, Optical Observations
- GRB 140423A: Swift-XRT refined Analysis
- GRB 140423A: Swift-BAT refined analysis
- GRB 140423A: MITSuME Okayama Optical Observation
- Swift Trigger 596958 is positionally consistent with V* DG CVn/2XMM J133146.4+291635
- Swift Trigger 596958 is probably the flare star: DG CVn
- GRB 140423A: Further Observations with Swift/UVOT
- GRB 140423A: KAIT Optical Detection
- GRB 140423A: Nanshan optical upper limit
- GRB 140423A: P60 Observations
- GRB 140423A: Fermi GBM observation
- GRB 140423A: KWFC z-band photometry
- GRB 140423A: Gemini-N redshift
- GRB 140419A, LOAO R-band observations
- GRB 140423A: ISON-MN early photometry and correction to the GCN circ. 16143
- GRB 140423A: Swift/UVOT detection of a possible counterpart
- GRB 140423A: Swift-XRT observations
- GRB 140423A: ROTSE-III Detection of Optical Counterpart
- GRB 140423A optical observations with pODI/WIYN at KPNO
- GRB 140423A: optical afterglow candidate
- GRB 140423A: Swift detection of a burst
- GRB 140419A: Mondy optical observations
- GRB 140419A: Refined NOT photometry
- GRB 140419A: Continued RATIR Optical and NIR Observations
- GRB140419A: NOT optical observations
- GRB 140419A: KAIT Refined Analysis
- GRB 140419A: Continued RATIR Optical and NIR Observations
- Swift Trigger 596641 is not a GRB
- Konus-Wind observation of GRB 140419A
- GRB 140419A, Optical Observations
- GRB 140419A: MITSuME Ishigakijima Optical Observation
- GRB 140419A: MITSuME Okayama Optical Observation
- GRB 140419A: Swift UVOT refined analysis
- GRB 140419A: P60 Observations
- GRB 140419A: Swift-XRT refined Analysis
- GRB 140419A: Swift-BAT refined analysis
- GRB 140419A: Gemini-N redshift
- GRB140419A: UVOT detects fading afterglow in white but not in u filter
- GRB 140419A: CARMA early 3mm detection
- GRB 140419A: RATIR Optical and NIR Observations
- GRB 140419A: ROTSE-III Detection of Optical Counterpart
- GRB 140419A (Swift trigger 596426) : KAIT optical candidate
- GRB 140419A: Swift detection of a burst with optical afterglow
- Konus-Wind observation of GRB 140416A
- IPN Triangulation of GRB 140416A (long/very intense)
- GRB 140416A: Fermi GBM detection
- GRB 140414A: Swift/UVOT Upper Limit
- GRB 140414A: Swift-XRT observations
- GRB 140414A: TNG optical observations
- GRB 140414A: Swift-BAT refined analysis
- GRB 140414A: Short burst found in ground analysis of BAT slew data
- GRB 140413A: Swift/UVOT Observations of the Optical Afterglow
- GRB 140412A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 140413A
- GRB 140413A: Swift-XRT refined Analysis
- GRB 140413A: Swift-BAT refined analysis
- GRB 140412A: Swift-XRT refined Analysis
- GRB 140412A: Swift-BAT refined analysis
- GRB 140413A: TAROT La Silla observatory optical observations
- GRB 140413A: GROND afterglow candidate
- Swift Trigger 595616: a possible GRB
- GRB 140412A: Swift detection of a burst
- GRB 140408A: 1.5m OSN optical upper limit
- Swift Trigger 595345 is not an astrophysical source
- Swift-BAT trigger 595162 is noise
- GRB 140408A: MITSuME Akeno Optical observation
- Fermi418277210: iPTF optical observations
- GRB 140408A: RATIR Optical Upper Limits
- GRB 140408A: Swift-BAT refined analysis