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').
17435 results found.
- LXT 240402A/GRB 240402B: Swift follow-up observations
- GRB 240414A: Mondy optical observations
- GRB 240415A: Prompt Swift-XRT observations
- GRB 240415A: Swift detection of a burst
- GRB 240414A: Swift-XRT refined Analysis
- GRB 240414A: Enhanced Swift-XRT position
- GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- GRB 240414A: Skynet Optical Afterglow Observations
- Swift GRB 240414A: Global MASTER-Net observations report
- IPN triangulation of GRB 240410A
- IPN triangulation of GRB 240411A
- GRB 240414A : MITSuME Akeno optical upper limits
- GRB 240414A: Swift detection of a burst
- GRB 240411B: Swift-BAT refined analysis
- GRB 240411B: Swift-XRT refined Analysis
- GRB 240411B: 1.3m DFOT Optical observations
- GRB 240411B: Enhanced Swift-XRT position
- GRB 240411B: Swift detection of a burst
- EP240408A: MASTER optical observations
- EP240408a: GROND detection of a candidate counterpart
- EP240408a: Swift follow-up observation
- Swift Trigger 1220736: detection of 4U 1543-62.
- Swift satellite resumes pointed science observations
- GRB 240318A: Fermi GBM Observation
- Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
- GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
- GRB 240318A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
- GRB 240317B: Swift/BAT-GUANO Angular Error Correction
- GRB 240317B: Fermi GBM Observation
- Swift satellite in safe mode
- GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
- Einstein Probe detected of a fast X-ray transient EP240315a
- GRID detection of GRB 240306A
- Swift Triggers 1220155, 1220156, 1220157, 1220158, 1220160 and 1220161 were not astrophysical
- Swift Triggers 1220093, 1220094, 1220095 and 1220096 are not astrophysical
- Swift Triggers 1220090, 1220091 and 1220092 are not astrophysical
- Swift triggers 1219917, 1219917 and 1219922 were not astrophysical
- Swift Trigger 1219909 and 1219910 are not a astrophysical
- Swift Trigger 1219905 is not a GRB
- Swift Trigger 1219874 is not astrophysical
- Swift GRB240309.61: Global MASTER-Net observations report
- Swift Trigger 1219325 is not a GRB
- GRB 240306A: Fermi GBM observation
- Konus-Wind detection of GRB 231118A
- GRB 240306A: AstroSat CZTI detection
- GRB 240306A: Swift/BAT-GUANO detection of a burst
- GRB 240305A: Fermi GBM observation
- Swift GRB240305.18: Global MASTER-Net observations report
- Swift GRB240305.16: Global MASTER-Net observations report
- GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 240218A: Chandra Detection and Jet Break Confirmation
- Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
- Swift Trigger 1218696: Another trigger on Swift J151857.0-572147
- Swift Trigger 1218645: Another detection of Swift J151857.0-572147
- Swift J151857.0-572147: Swift-BAT refined analysis
- GRB 240225B: Swift-XRT afterglow detection
- Swift detection of Swift J151857.0-572147
- Swift GRB 240303A: Global MASTER-Net observations report
- Swift J151857.0-572147: Confirmation of a new galactic transient
- GRB 240215A: Swift-XRT afterglow detection
- GRB 240303A: Swift detection of a burst
- GRB 240225A (short): Glowbug gamma-ray detection
- Swift BAT Triggers 1218081 and 1218082 are not astrophysical
- GRB 240225B: Swift ToO observations
- GRB 240225B: 3.6m DOT observation
- Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
- Swift Trigger 1217799 is not a GRB
- Swift-BAT triggers 1217733 - 1217736 are not astrophysical events
- Swift-BAT triggers 1217729-1217732 are not astrophysical
- GRB 240225B: Nanshan/HMT optical afterglow detection
- GRB 240225B: Swift-XRT observations
- GRB 240225B: GOTO detection of a candidate optical afterglow
- GRB 240225B: Tiled Swift observations
- Transient EPW20240219aa: Xinglong-2.16m optical upper limit
- GRB 240225A: Swift/BAT-GUANO detection of a short burst
- GRB 240222A: GRBAlpha detection
- Swift-BAT triggers 1217218-1217222 are not astrophysical
- Transient EPW20240219aa: Mondy optical observations
- Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
- Swift BAT Sub-Threshold Detection of EPW20240219aa
- GRB 240222A: GECAM detection of a burst
- GRB 240222A: Swift-BAT refined analysis
- GRB 240222A: Swift-XRT refined Analysis
- Swift-BAT triggers 1216907-1216911 are not astrophysical
- GRB 240222A: Fermi GBM Observation
- GRB 240222A: Swift/UVOT Upper Limits
- Swift GRB 240222A: Global MASTER-Net observations report
- Swift Trigger 1216864 is not an astrophysical event
- GRB 240222A: Swift detection of a burst
- Swift-BAT triggers 1216751 and 1216753 are not astrophysical events
- Swift-BAT triggers 1216743-1216748 are not astrophysical
- Swift GRB240221.92: Global MASTER-Net observations report
- GRB 240218A: MeerLICHT upper limits
- GRB 240215B: Fermi GBM Observation
- GRB 240218A: LBT H-band detection
- GRB 240218A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 240218A
- GRB 240218A: Swift-XRT refined Analysis
- GRB 240218A: VLT/X-shooter redshift of z = 6.782