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.
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"11523 results found.
- IPN Triangulation of GRB 181212A (long)
- GRB 181212A: Fermi GBM Detection
- GRB 181126B: KAIT Follow-Up Observations of a Fermi Short GRB (Trigger 564897175)
- MASTER OT J063515.49-624002.9 of Fermi trigger 565936249: optical observations in SAAO
- MASTER: OTs detection during Fermi alert trigger 565936249 early observations
- GRB 181126B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 564897175)
- Fermi-GBM Observations During Four New GW-Detected BBH Mergers (Correction)
- Fermi-GBM Observations During Four New GW-Detected BBH Mergers
- GRB 181201A: Insight-HXMT/HE detection
- GRB 181201A: Fermi-LAT detection
- Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection
- GRB 181126A: Fermi GBM observation
- GRB 181125A: Fermi GBM observation
- GRB 181020A: AstroSat CZTI detection
- GRB 181119A: Insight-HXMT/HE detection
- GRB 181120A: Fermi GBM observation
- GRB 181120A: Fermi-LAT detection
- Fermi GRB 181105.31: Global MASTER Net optical observations
- GRB 181028A: Insight-HXMT/HE detection
- GRB 181028A: CALET Gamma-Ray Burst Monitor detection
- GRB 181026A: AstroSat CZTI detection
- Konus-Wind observation of GRB 181028A
- IPN Triangulation of GRB 181028A (long)
- GRB 181028A: Fermi GBM observation
- GRB 181028A: Fermi-LAT detection
- GRB 181027A: Fermi GBM detection
- GRB 180728B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 554505003)
- Fermi-LAT Gamma-ray Observations of IceCube-181023A
- IceCube-181023A - IceCube observation of a high-energy neutrino candidate event
- Konus-Wind observation of GRB 181020A
- GRB 181020A: Swift/UVOT Detection
- GRB 181020A: Global MASTER Net OT observations
- GRB 181020A: VLT/X-shooter spectroscopy and redshift
- GRB 181020A: Fermi GBM detection
- GRB 181020A: Fermi-LAT detection
- GRB 181014A: Insight-HXMT/HE detection
- Fermi GBM Observation of IceCube-181014A
- Fermi-LAT Gamma-ray Observations of IceCube-181014A
- GRB180913A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 558557292)
- GRB 181010A: Fermi GBM observation
- IPN Triangulation of GRB 181008B (long)
- GRB 181008A: Insight-HXMT/HE detection
- INTEGRAL detections of the prompt gamma-ray emission of GRB 180914B
- Konus-Wind observation of GRB 180923A
- GRB 180923B - GBM Correction to GCN 23263
- GRB 180923B: Fermi GBM detection
- GRB 180914B: OSN Detection and light curve/SED analysis
- Konus-Wind observation of GRB 180914A
- GRB 180914B: DDOTI/OAN Detection and Confirmation of Fading
- GRB 180914B: AstroSat CZTI detection
- GRB 180914A: AstroSat CZTI detection
- IPN Triangulation of GRB 180914A (long)
- GRB 180914B: VLT/X-shooter spectroscopic redshift
- GRB 180914B: AGILE/MCAL refined analysis
- GRB180914B: Swift UVOT detection of an optical afterglow
- Konus-Wind of the very bright GRB 180914B
- GRB 180914B: RATIR Optical and NIR Observations
- GRB 180914B: Swift-XRT afterglow detection
- GRB 180914A: RATIR Optical and NIR Observations
- GRB 180914B: Tiled Swift observations
- GRB 180914B: Fermi-LAT detection
- GRB 180914A: MASTER automatic inspection
- GRB 180914A: Swift-XRT observations
- GRB 180914A: Tiled Swift observations
- GRB 180914A: Fermi GBM detection
- GRB 180914A: Fermi-LAT detection
- Fermi-LAT Gamma-ray Observations of IceCube-180908A
- Fermi GBM trigger 557852757/180905629 is not a GRB
- Konus-Wind observation of GRB 180828A
- GRB 180828A: AstroSat CZTI detection
- GRB 180828A: Fermi GBM observation
- Fermi GBM trigger 557014342/180826925 is not a GRB
- Fermi GBM trigger 557008382/180826856 is not a GRB
- GRB 180818B: 1.5m OSN optical afterglow candidate
- GRB180806A: confirmation of the X-ray afterglow
- GRB 180818B: Fermi GBM observations
- GRB 180812A: Fermi GBM detection
- Konus-Wind observation of GRB 180809B
- MASTER: OT detection during two Fermi GBM triggers (555263883 and 555263883) error boxes inspection in 22.5 mag SDSS galaxy direction
- GRB 180806A: AstroSat CZTI detection
- Konus-Wind observation of GRB 180806A
- GRB 180809A: Fermi GBM observation
- GRB 180809A: CALET Gamma-Ray Burst Monitor detection
- GRB 180728A: AstroSat CZTI detection
- GRB180806A: correction to Circular 23097
- GRB 180723A: AstroSat CZTI detection
- GRB 180806A: NOT optical observations
- GRB 180806A: Swift-XRT afterglow detection
- GRB 180806A/180806.98: RATIR Optical Observations of MASTER OT J004613.05+242014.1
- GRB 180806A: Fermi GBM detection
- GRB 180806A/180806.94: Refined COATLI Photometry of MASTER OT J004613.05+242014.1
- GRB 180806A: Swift ToO observations
- GRB 180806.94: COATLI Detection of MASTER OT J004613.05+242014.1 and Confirmation of Fading
- GRB 180806.94: MASTER possible OT detection in Fermi GMB trigger 555287944 error box
- GRB 180805B: Fermi GBM detection
- Fermi Trigger 554765006: MASTER optical inspection
- Fermi GBM trigger 554730582/180731493 is not a GRB
- Konus-Wind observation of the bright nearby GRB 180728A
- GRB 180703B: CALET CAL gamma-ray analysis
- GRB 180728B: Fermi GBM detection