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"19618 results found.
- GRB 220222A: CALET Gamma-Ray Burst Monitor detection
- Swift GRB 220302A: Global MASTER-Net observations report
- GRB 220302A: Swift detection of a burst
- GRB 220228A: Fermi-LAT detection
- Konus-Wind detection of GRB 220222A
- IPN triangulation of GRB 220222A
- GCN Circ.draft on GRB 220222A
- GRB 220219B: Swift-XRT observations
- ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
- GRB 220219B: Swift ToO observations
- GRB 220222A: Swift/BAT-GUANO detection outside the coded FOV
- ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
- IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
- GRB 220218A: BOOTES-5/JGT optical upper limit
- GRB 220218A: Swift detection of a burst
- Swift GRB220218.94: Global MASTER-Net observations report
- Swift resumes pointed science observations
- Konus-Wind detection of GRB 220211A
- GRB 220211A: Fermi GBM observation
- GRB 220210A: Mondy, AbAO and Terskol optical upper limits
- IPN triangulation of GRB 220211A (short)
- GRB 220210A: Insight-HXMT/HE detection
- GRB 220211A: Swift/BAT-GUANO detection outside the coded FOV (short)
- GRB 220210A: 1.5m OSN optical upper limit
- GRB 220210A: Fermi GBM detection
- GRB 220210A: Fermi-LAT detection
- GRB 220210A: AGILE detection
- GRB 220210A: BOOTES-5/JGT optical afterglow candidate
- GRB 220210A: Swift/BAT-GUANO localization
- GRB 210919A: Maidanak optical observations
- GRB 210919A: SPI-ACS/INTEGRAL observation and evaluation of Ep
- Konus-Wind detection of GRB 220203A
- GRB 220203A: GECAM detection
- GRB 220203A: Swift/BAT-GUANO detection outside the coded FOV
- IPN triangulation of GRB 220203A (short)
- IPN triangulation of GRB 220130A
- Swift Reaction Wheel Anomaly Update (4 Feb 2022)
- GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
- GRB 220131B: Swift/BAT-GUANO detection outside the coded FOV
- IPN triangulation of GRB 220128A (long)
- IPN triangulation of GRB 220124A
- GRB 220117A: Terskol and AbAO optical upper limits
- GRB 220118A: TARGET optical upper limit
- GRB 220117B: TARGET optical upper limit
- GRB 220117A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
- IPN triangulation of GRB 211226A
- GRB 220117C: Fermi GBM Observation
- GRB 220118A: 2.2m CAHA/CAFOS detections
- GRB 220118A: Fermi GBM detection
- GRB 220118A: COATLI Optical Observations
- GRB 220117C: Swift/BAT-GUANO arcminute localization
- Swift currently in safe hold with science slews disabled
- GRB 220118A: Swift-BAT refined analysis
- GRB 220118A: Swift/UVOT Detection
- GRB 220118A: GIT optical observations
- GRB 220118A: Enhanced Swift-XRT position
- Swift GRB220118.50: Global MASTER-Net observations report
- GRB 220118A: MITSuME Akeno optical observation
- Swift GRB 220118A: Global MASTER-Net observations report
- GRB 220118A: Swift detection of a burst with an optical counterpart
- GRB 220117A: MITSuME Akeno optical upper limits
- Fermi GBM Sub-Threshold Detection of GRB 220117A
- GRB 220117B: Swift-BAT refined analysis
- GRB 220117A: Swift-BAT refined analysis
- GRB 220117B: Swift/UVOT Upper Limits
- GRB 220117A: Swift/UVOT Upper Limits
- GRB 220117A: LCO Optical Observations
- GRB 220117B: Swift-XRT refined Analysis
- GRB 220117A: Swift-XRT refined Analysis
- GRB 220117B: Nanshan/NEXT optical upper limit
- GRB 220117B: MITSuME Akeno optical upper limits
- GRB 220117B: Enhanced Swift-XRT position
- GRB 220117A: Enhanced Swift-XRT position
- GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
- Swift GRB 220117A: Global MASTER-Net observations report
- Swift GRB 220117B: Global MASTER-Net observations report
- GRB 220117B: Swift detection of a burst
- GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
- GRB 220117A: Swift detection of a burst
- GRB 220101A: The most powerful GRB and BDHN I in 26 years
- GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
- Konus-Wind detection of GRB 220101A
- Konus-Wind detection of GRB 220107A
- Confirmation of the X-ray afterglow of GRB 220107B
- GRB 220107A: 6m BTA spectroscopic redshift
- GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220101A: SAO RAS optical observations
- GRB 220107A: AbAO and Terskol optical observations
- GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
- GRB 220107A: Nanshan/NEXT optical observations
- GRB 220107A: Swift/UVOT Detection
- GRB 220107A: MITSuME Akeno optical observation
- GRB 220107B: AstroSat CZTI detection
- GRB 220107B: Swift-XRT afterglow detection
- GRB 220107A: Swift-XRT afterglow detection
- GRB 220107B: Fermi-LAT detection
- GRB 220107A: AstroSat CZTI detection
- GRB 220107B: Tiled Swift observations
- GRB 220107A: Fermi GBM observations
- GRB 220107A: Swift ToO observations