GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"- GRB 140509B: MAXI/GSC detection
- GRB 140509A: Swift/UVOT Detection and photo-z
- GRB 140509A: Swift-BAT refined analysis
- VHE gamma-ray observations by MAGIC of SWIFT Trigger 596958
- GRB 140509A: Swift-XRT refined Analysis
- GRB 140508A: RATIR Optical and NIR Observations
- GRB 140508A: Optical Observations via Virtual Telescope
- Konus-Wind observation of GRB 140508A
- GRB 140509A: Enhanced Swift-XRT position
- GRB 140508A: Swift-XRT observations
- GRB 140508A: WHT spectroscopy
- GRB 140509A: Swift detection of a burst with an optical counterpart
- GRB 140508A: NOT photometry and spectroscopy
- GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
- GRB 140508A: 1.23m CAHA BVRI-band observations
- GRB 140508A: iPTF optical transient candidate
- IPN triangulation of GRB 140508A
- GRB 140508A: Fermi GBM detection
- Konus-Wind observation of GRB 140506A
- GRB 140430A: MITSuME Akeno upper limits
- GRB 140502A: ISON-NM early optical limit
- GRB 140506A: Fermi GBM Detection
- GRB 140506A: Swift/UVOT Detection
- GRB 140506A: Swift-BAT refined analysis
- GRB 140506A: VLT/X-shooter spectroscopy
- GRB 140506A: Swift-XRT refined Analysis
- GRB 140506A: Enhanced Swift-XRT position
- GRB 140506A: Swift detection of a burst with an optical counterpart
- Konus-Wind observation of GRB 140423A
- GRB 140430A: iTelescope.Net T16 Optical Observation
- GRB 140430A: r'-band STELLA-I observations
- GRB 140502A: Swift/UVOT Upper Limits
- GRB 140502A: MITSuME Okayama upper limits
- GRB 140502A: Swift-BAT refined analysis
- GRB 140502A: Swift-XRT refined Analysis
- GRB 140502A: Enhanced Swift-XRT position
- GRB 140430A: BVR-band IAC80 observations
- Swift Trigger 597860 is probably not a GRB
- GRB 140502A: Fermi GBM observation
- GRB 140502A: Swift detection of a burst
- GRB 140430A: Further VATT Optical Observations
- GRB 140430A: Swift-BAT refined analysis
- GRB 140501A: Fermi GBM detection
- GRB 140430A: Swift/UVOT Observations
- GRB 140430A: Swift-XRT refined Analysis
- GRB 140430A: VATT Optical Observations
- GRB 140430A: Enhanced Swift-XRT position
- 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: Kanata/HONIR Optical and NIR 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: Enhanced Swift-XRT position
- 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