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"
6096 results found.
- GRB 220606A: Fermi GBM observation
- GRB 220606B: Fermi GBM Observation
- GRB 220606B: Swift follow-up observations
- GRB 220528A: Fermi GBM Observation
- Konus-Wind observation of GRB 220527A
- GRB 220527A: MeerLICHT afterglow observations
- GRB 220527A: Swift/UVOT detection
- GRB 220527A: Swift-XRT afterglow detection
- GRB 220527A: Fermi GBM Observation
- GRB 220527A: Fermi-LAT detection
- Fermi-LAT Gamma-ray Observations of IceCube-220524A
- GRB 220521A: Gemini Observations
- GRB 220521A: Fermi GBM detection
- GRB 220521A: Swift-XRT refined Analysis
- GRB 220521A: NOT optical afterglow detection
- GRB 220518A: Swift-XRT refined Analysis
- Continued Chandra monitoring of GW170817 at ~4.8 yr post-merger
- GRB 220514A: GRANDMA Optical Afterglow Observations
- GRB 220514A: Fermi GBM observation
- GRB 220514B: Swift-XRT observations
- GRB 220511A: Swift-XRT afterglow detection
- Fermi-LAT Gamma-ray Observations of IceCube-220513A
- IceCube-220513A: No significant detection in HAWC
- GRB 220514A: MeerLICHT optical afterglow candidate
- IceCube-220509A: No significant detection in HAWC
- GRB 220511A: Fermi GBM observation
- GRB 220511A: Swift-XRT observations
- Fermi-LAT Gamma-ray Observations of IceCube-220509A
- GRB 220506A: GIT optical upper limit.
- GRB 220506A: Swift-XRT afterglow detection
- GRB 220430A: GIT optical upper limits
- Fermi-LAT Gamma-ray Observations of IceCube-220501A
- GRB 220501A: Fermi GBM observation
- GRB 220430A: Swift-XRT refined Analysis
- GRB 220426A: Swift-XRT and UVOT observations
- GRB 220427A: Swift-XRT refined Analysis
- GRB 220426A: Fermi GBM detection
- Fermi-LAT Gamma-ray Observations of IceCube-220425A
- Fermi-LAT Gamma-ray Observations of IceCube-220424A
- GRB 220421A: Fermi GBM observation
- Fermi-LAT Gamma-ray Observations of IceCube-220421A
- GRB 220418B: Swift-XRT observations
- GRB 220418B Fermi GBM observation
- GRB 220403C: Further Swift-XRT observations
- GRB 220417A: Fermi GBM detection
- GRB 220412B: Fermi GBM observation
- GRB 220408B: Fermi GBM observation
- GRB 220412B: Swift-XRT observations
- GRB 220408B: Fermi-LAT detection
- GRB 220408A: HCT optical upper limit
- GRB 220412B: GIT optical upper limit
- GRB 220412A: Swift-XRT refined Analysis
- GRB 220408A: GRANDMA observations
- GRB 220403B: 1.3m DFOT Optical upper limit
- GRB 220403C: Swift-XRT observations
- GRB 220408A: Swift-XRT refined Analysis
- GRB 220408A: GIT optical upper limit
- GRB 220408A: Fermi GBM observation
- Chandra upper limit at the location of GRB 220408A
- Fermi-LAT Gamma-ray Observations of IceCube-220405B
- Fermi-LAT Gamma-ray Observations of IceCube-220405A
- GRB 220403B: Fermi GBM detection
- GRB 220403B: Swift-XRT refined Analysis
- GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
- GRB 220401A: Fermi GBM observation
- GRB 220325A: Swift-XRT refined Analysis
- GRB 220325A: 1.3m DFOT Optical upper limit
- GRB 220317A: Fermi GBM detection
- GRB 220319A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-220317A
- GRB 220311A: Fermi GBM observation
- GRB 220310C: Fermi GBM observation
- GRB 220310C: Swift-XRT observations
- GRB 220310A: GIT confirmation of optical afterglow.
- GRB 220308B: Fermi GBM detection
- IceCube-220306A: No significant detection in HAWC
- IceCube-220303A: No significant detection in HAWC
- GRB 220304A Fermi GBM detection
- Fermi-LAT Gamma-ray Observations of IceCube-220306A
- GRB 220306B: Swift-XRT refined Analysis
- GRB 220306B: Fermi GBM observation
- Fermi-LAT Gamma-ray Observations of IceCube-220304A
- GRB 220305A: Swift-XRT refined Analysis
- Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
- GRB 220305A: Fermi GBM observation
- Fermi-LAT Gamma-ray Observations of IceCube-220303A
- GRB 220302A: Swift-XRT refined Analysis
- GRB 220228A: Fermi GBM observation
- GRB 220228A: Fermi-LAT detection
- Fermi-LAT Gamma-ray Observations of IceCube-220225A
- Konus-Wind observation of GRB 220219B
- GRB 220219B: Swift-XRT observations
- ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
- ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
- Fermi-LAT Gamma-ray Observations of IceCube-220221A
- ZTF22aaajecp: GIT optical follow-up observations
- GRB 220211A: Fermi GBM observation
- GRB 220209A: Fermi-LAT detection
- GRB 220210A: Fermi-LAT detection
- Fermi GRB 220211A: Global MASTER-Net observations report