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"
32130 results found.
- GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
- GRB 240415A: Earliest optical followup with the Kinder observations
- GRB 240414A: GMG observation
- GRB 240415A: Enhanced Swift-XRT position
- GRB 240415B: Swift ToO observations
- GRB 240415B: Swift/BAT-GUANO Correction
- GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
- GRB 240415A: OHP/T193 optical observations
- GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
- GRB 240415A: SAO RAS optical observations
- GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
- GRB 240414A: Fermi GBM Observation
- Fermi GRB 240415A: Global MASTER-Net observations report
- GRB 240415A: Mondy optical transient detection
- GRB 240414A: Photometric observation from 2.2m CAHA
- GRB 240414A: Swift/UVOT Detection
- LXT 240402A/GRB 240402B: Swift follow-up observations
- GRB 240414A: Mondy optical observations
- GRB 240414B: Fermi GBM Final Real-time Localization
- GRB 240414A: AKO Optical Upper Limit
- GRB 240415A: Prompt Swift-XRT observations
- GRB 240415A: Swift detection of a burst
- GRB 240415A: Fermi GBM Final Real-time Localization
- EP240413a: Upper limits from GECAM-B Observation
- GRB 240414A: Swift-XRT refined Analysis
- GRB240414A : J-band upper limits from WINTER
- GRB 240414A: Enhanced Swift-XRT position
- GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
- 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: Redshift confirmation from GTC/OSIRIS+
- GRB 240414A : OHP/T193 redshift determination
- GRB 240414A : OHP/T193 optical counterpart detection
- GRB 240414A: Swift detection of a burst
- GRB 240411B: CrAO/ZTSh optical observations
- GRB 240411B: Kinder observations with Lulin observatory
- GRB 240411B: HiPERCAM/GTC observation
- GRB 240411B: Swift-BAT refined analysis
- GRB 240411B: Swift-XRT refined Analysis
- GRB 240411B: 1.3m DFOT Optical observations
- GRB 240411A: GRBAlpha detection
- GRB 240411B: OHP/T193 optical observations
- GRB 240405A: Glowbug gamma-ray detection
- GRB 240411B: Enhanced Swift-XRT position
- GRB 240411B: LCO optical afterglow detection
- GRB 240411B: Swift detection of a burst
- GRB 240408B: GRBAlpha detection
- GRB 240411A: Fermi GBM Final Real-time Localization
- EP240408a: Upper limits from GECAM-B Observation
- GRB 240405A: GRBAlpha detection
- GRB 240408B: AstroSat CZTI detection
- Fermi GRB 240408A: Global MASTER-Net observations report
- GRB 240408A: Fermi GBM Final Real-time Localization
- GRB 240407A: BALROG localization (Fermi Trigger 734144396 / GRB 240407042)
- GRB 240402C: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 240407A: Global MASTER-Net observations report
- GRB 240407A: Fermi GBM Final Real-time Localization
- LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
- Fermi GRB 240405B: Global MASTER-Net observations report
- GRB 240405B: Fermi GBM Final Real-time Localization
- GRB 240402C: Glowbug gamma-ray detection
- GRB 240405A: Fermi GBM Final Real-time Localization
- GRB 240402C: GRBAlpha detection
- GRB 240331A: GRBAlpha detection
- LXT 240402A/GRB 240402B: GECAM-C refined analysis
- GRB 240403B: Glowbug gamma-ray detection
- GRB 240403A: Glowbug gamma-ray detection
- LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
- Konus-Wind detection of LXT 240402A/GRB 240402B
- GRB/FXT 240402B: Kinder optical counterpart candidate
- GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
- GRB 240403A: Fermi GBM Detection
- LXT 240402A: EP-FXT detection of the X-ray afterglow
- Fermi GRB 240404A: Global MASTER-Net observations report
- GRB 240404A: Fermi GBM Final Real-time Localization
- GRB 240402B: GWAC-F50A optical upper limit
- GRB 240402B: GECAM-C detection
- GRB 240403A: BALROG localization (Fermi Trigger 733838255 / GRB 240403498)
- Fermi GRB 240402A: Global MASTER-Net observations report
- GRB 240402A: Fermi GBM Final Real-time Localization
- IBAS Alert n.10651 not a GRB
- GRB 240329A: Glowbug gamma-ray detection
- GRB 240324A: AstroSat CZTI detection of a short burst
- GRB 240331A: AstroSat CZTI detection
- GRB 240329A: AstroSat CZTI detection
- GRB 240331A: Fermi GBM Final Real-time Localization
- GRB 240329A: GRBAlpha detection
- Fermi GRB 240329A: Global MASTER-Net observations report
- GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
- GRB 240329A: Fermi GBM Final Real-time Localization
- Fermi GRB 240328B: Global MASTER-Net observations report
- Fermi GRB 240328A: Global MASTER-Net observations report
- GRB 240328C: Glowbug gamma-ray detection
- GRB 240328B: Fermi GBM Final Real-time Localization
- GRB 240328A: Fermi GBM Final Real-time Localization
- X-ray transient EP 240315a: Second epoch Chandra observations