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.
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"11552 results found.
- Fermi GBM Sub-Threshold Detection of GRB 251105B
- Fermi GRB 251105A: Global MASTER-Net observations report
- GRB 251105A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 783986701/251104920 is not a GRB
- GRB 251103B: Fermi GBM observation
- GRB 251028A: Insight-HXMT/HE detection
- GRB 251103A: WFST optical observations
- GRB 251103A: OHP/T193 optical observations
- GRB 251103A: Xinglong 2.16m optical detection
- GRB 251103A: Insight-HXMT detection
- GRB 251103A: KAIT optical observations
- GRB 251103B: Nanshan/HMT optical upper limit
- GRB 251013C: 7DT detection and Medium-band SED of Afterglow
- GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 251103B: MITSuME Akeno optical upper limits
- Fermi GRB 251103A: Global MASTER-Net observations report
- GRB 251103A: J-band detection with WINTER
- GRB 251103B: GROWTH-India Telescope optical upper limits
- GRB 251103A: Kilonova-Catcher optical afterglow detection
- GRB 251103B: Fermi GBM Final Real-time Localization
- GRB 251103A: Fermi GBM Observation
- GRB 251103A: SVOM/GRM observation
- GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
- GRB 251103A: GOTO optical afterglow detection
- GRB 251102A: AstroSat CZTI detection
- GRB 251103A: NOT spectroscopic redshift z = 0.76
- GRB 251103A: Fermi GBM Final Localization
- GRB 251102B: Fermi GBM Final Real-time Localization
- Fermi GRB 251102A: Global MASTER-Net observations report
- GRB 251102A: Fermi GBM Final Real-time Localization
- GRB 251031A: Fermi GBM Observation
- GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
- Konus-Wind detection of GRB 251028A
- GRB 251031A: BALROG localization (Fermi Trigger 783588065 / GRB 251031306)
- GRB 251031A: Fermi GBM Final Real-time Localization
- GRB 251025C: SVOM/GRM observation
- GRB 251028A: GECAM-B detection
- GRB 251028A: SVOM/GRM observation
- GRB 251028A: Fermi GBM Observation
- GRB 251022A: Swift-XRT confirmation of fading
- GRB 251026B: LBT near-infrared observations
- GRB 250926B: VZLUSAT-2 detection
- GRB 250926A: VZLUSAT-2 detection
- GRB 251026B: Fermi GBM Observation
- GRB 251028B: Fermi/GBM observation
- GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
- GRB 251028B: Glowbug gamma-ray detection
- GRB 251028A: Glowbug gamma-ray detection
- GRB 251028B: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 251028B: Global MASTER-Net observations report
- GRB 251028B: Fermi GBM Final Localization Correction
- GRB251026B: PRIME H-band upper limit
- GRB 251028A: BALROG localization (Fermi Trigger 783314796 / GRB 251028143)
- GRB 251028A: Fermi GBM Final Real-time Localization
- GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
- GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
- GRB 251025C: Glowbug gamma-ray detection
- Fermi-LAT Gamma-ray Observations of IceCube-251025A
- Konus-Wind detection of GRB 251022A
- GRB 251022A: SVOM/GRM observation
- GRB 251026B: Swift ToO observations
- Konus-Wind detection of GRB 251016A (short/hard)
- GRB 251026B: Tentative GOTO optical counterpart candidate
- GRB 251025C: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 251026B: Global MASTER-Net observations report
- Fermi GRB 251025C: Global MASTER-Net observations report
- GRB 251026B: Fermi GBM Final Localization
- GRB 251023A: SVOM/GRM observation
- GRB 251025C: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 251016B
- IceCube-251025A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 251003A: VLA Detection
- GRB 251022A: KAIT optical observations
- GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
- GRB 251022A: Swift-XRT detection of GOTO25iym
- GRB 251022A: GROWTH-India Telescope optical observations
- GRB 251022A: Fermi GBM Observation
- GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
- GRB 251023A: Glowbug gamma-ray detection
- IPN triangulation of GRB 251016B
- GRB 251013C: further SAO RAS optical observations
- GRB 251022A: COLIBRÍ optical observations
- GRB 251013C: ISON-Castelgrande observatory optical observations
- GRB 251022A: MASTER OT detection
- GRB 251022A: DDOTI Optical Detection
- Fermi GRB 251023A: Global MASTER-Net observations report
- GRB 251022A: GOTO optical counterpart detection
- GRB 251023A: Fermi GBM Final Localization Correction
- GRB 251022A: Fermi-LAT detection
- GRB 251016B: Fermi GBM Detection
- GRB 251022A: Tiled Swift observations
- GRB 251022A: Fermi GBM Final Real-time Localization
- GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
- GRB 251016A: SVOM/ECLAIRs refined analysis
- Fermi-LAT gamma-ray observations of IceCube-251018A
- GRB 251016A: Fermi GBM Observation
- GRB 251018A: Fermi GBM Observation
- GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
- Fermi trigger No 782500909: Global MASTER-Net observations report
- GRB 251016A: HXMT/HE detection