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"28221 results found.
- LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
- LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
- IPN triangulation of GRB 251108C
- GRB 251114A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
- GRB 251113A: Fermi GBM Final Real-time Localization
- GRB 251112A: Swift/UVOT Upper Limits
- LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
- GRB 251112A: Swift-XRT refined Analysis
- GRB 251108C: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
- GRB 251112B: MAXI/GSC detection
- GRB 251108B: Glowbug gamma-ray detection
- Swift Trigger 1413695: a possible GRB 251112A
- LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
- GRB251111A: 1.3m DFOT optical upper limit
- GRB 251106B: Glowbug gamma-ray detection of a likely short burst
- GRB 251111A: Swift-XRT afterglow detection
- GRB 251111A: Swift-XRT observations
- GRB 251111A: EP-FXT counterpart detection
- GRB 251013C: Chandra X-ray observations and jet break detection
- GRB 251111A: SVOM/VT optical observations with VHF data
- GRB 251111A: KAIT optical upper limit
- GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
- GRB 251111A: SVOM detection of a soft burst
- GRB 251106A: Swift/UVOT Upper Limits
- GRB 251105B: Insight-HXMT/HE detection
- GRB 251106B: Insight-HXMT detection
- GRB 251105A: AstroSat CZTI detection
- GRB 251108A: Fermi GBM Final Localization Correction
- IPN triangulation of GRB 251105B (possible sGRB with EE)
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
- GRB 251106A: Swift-XRT afterglow detection
- Fermi GBM Sub-Threshold Detection of GRB 251106A
- GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
- GRB 251106A: SVOM detection of a burst
- GRB 251103B: AstroSat CZTI detection
- GRB 251025C: TERI Gamma-ray detection
- GRB 251016B: TERI Gamma-ray detection
- GRB 251016A: TERI Gamma-ray detection of a short burst
- GRB 250920C: TERI Gamma-ray detection
- GRB 251105C: Fermi GBM Final Localization Correction
- GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
- GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
- Fermi GBM Sub-Threshold Detection of GRB 251105B
- GRB 251103B: Swift/UVOT Upper Limits
- GRB 251105A: Fermi GBM Final Real-time Localization
- GRB 251103B: Fermi GBM observation
- GRB 251104A: SVOM detection of a burst
- GRB 251028A: Insight-HXMT/HE detection
- GRB 251103A: Optical afterglow detection by ZTF’s public survey
- GRB 251103A: WFST optical observations
- EP251102a: OHP/T193 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 251103B: MITSuME Akeno optical upper limits
- GRB 251103B: Swift-XRT refined Analysis
- GRB 251103A: J-band detection with WINTER
- GRB 251103B: GROWTH-India Telescope optical upper limits
- GRB 251103A: Kilonova-Catcher optical afterglow detection
- GRB 251103B: Enhanced Swift-XRT position
- GRB 251103B: Prompt enhanced Swift-XRT position
- GRB 251103B: Swift detection of a burst
- GRB 251103B: Fermi GBM Final Real-time Localization
- GRB 251103A: Swift/UVOT Detection
- GRB 251103A: Swift-XRT afterglow detection
- EP251102a: Einstein Probe detection of a fast X-ray transient
- GRB 251025B: OHP/T193 optical upper limit
- GRB 251103A: GOTO optical afterglow detection
- GRB 251102A: AstroSat CZTI detection
- GRB 251103A: NOT spectroscopic redshift z = 0.76
- GRB 251103A: BOOTES-2/TELMA optical afterglow
- GRB 251103A: LCO optical afterglow detection
- GRB 251103A: NOT optical afterglow candidate (duplicate submission)
- GRB 251103A: Fermi GBM Final Localization
- GRB 251103A: NOT optical afterglow candidate
- GRB 251103A: SVOM detection of a bright burst
- GRB 251102B: Fermi GBM Final Real-time Localization
- GRB 251102A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 251028A
- GRB 251031A: Fermi GBM Final Real-time Localization
- GRB 251028A: GECAM-B detection
- GRB 251022A: Swift-XRT confirmation of fading
- GRB 251026B: LBT near-infrared observations
- GRB 250926B: VZLUSAT-2 detection
- GRB 250926A: VZLUSAT-2 detection
- GRB 250925A: VZLUSAT-2 detection
- GRB 251026A/EP251026a: SVOM/VT optical counterpart
- GRB 251028B: Glowbug gamma-ray detection
- GRB 251028A: Glowbug gamma-ray detection
- GRB 251028B: CALET Gamma-Ray Burst Monitor detection
- GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening
- GRB 251028B: Fermi GBM Final Localization Correction
- GRB251026B: PRIME H-band upper limit
- GRB251025B: 3.6m DOT Optical Observations
- GRB 251028A: MAXI/GSC detection