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"28864 results found.
- GRB 260926A: Fermi GBM Final Real-time Localization
- The EP-WXT trigger 01709320726 is likely a flaring star
- GRB 260924A: COLIBRÍ optical observations
- GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
- EP260924a: J-band upper limit by SYSU 80cm infrared telescope
- GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
- GRB 260925A: Swift-XRT refined Analysis
- Swift Trigger 1513439 is probably not a GRB
- GRB 260925A: Swift/UVOT Upper Limits
- Konus-Wind detection of GRB 260924A
- GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
- GRB 260923A: Glowbug gamma-ray detection
- GRB 260924A: Optical follow-up observations with Kinder
- GRB 260925A: COLIBRÍ optical upper limits
- GRB 260925A: FRAM-Auger optical limit
- GRB 260924A: Ondrejov D50 optical afterglow detection
- EP260924a: J-band upper limit with WINTER
- GRB 260924A: SVOM/GRM observation
- GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
- GRB 260925A: Swift detection of a burst
- GRB 260923A: Insight-HXMT/HE detection
- GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
- GRB 260924A: Swift/UVOT Detection
- GRB 260924A: GROWTH-India Telescope optical observations
- GRB 260924A: Swift-BAT refined analysis
- GRB 260924A: NuSTAR detection of prompt emission
- GRB 260924A: Swift-XRT refined Analysis
- GRB 260921A: NuSTAR detection of prompt emission
- GRB 260921A: SVOM/GRM observation
- GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
- GRB 260924A: Fermi GRB Observation
- Konus-Wind detection of GRB 260921A (possible merger-origin)
- GRB 260924A: Fermi-LAT detection of a bright burst
- GRB 260924A: AstroSat CZTI detection
- GRB 260920A: SVOM/GRM observation
- GRB 260924A: NOT optical counterpart confirmation
- GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
- GRB 260922A: CALET Gamma-Ray Burst Monitor detection
- The EP-WXT trigger 01709319842 is likely a flaring star
- GRB 260924A: Swift detection of a burst
- GRB 260924A: Fermi GBM Final Real-time Localization
- Fermi GRB 260923A: Global MASTER-Net observations report
- GRB 260923A: Fermi GBM Final Real-time Localization
- GRB 260922A: Ondrejov D50 optical limit
- Fermi-LAT Gamma-ray Observations of IceCube-260919A
- Fermi-LAT Gamma-ray Observations of IceCube-260916A
- GRB 260922A: Swift-BAT refined analysis
- EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
- GRB 260922A: J-band upper limit with WINTER
- GRB 260922A: Swift/UVOT Upper Limits
- GRB 260922A: COLIBRÍ optical upper limits
- GRB 260922A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-260805A
- GRB 260920A: Glowbug gamma-ray detection
- GRB 260918A: SVOM/ECLAIRs refined analysis
- GRB 260922A: SVOM/C-GFT optical upper limit
- GRB 260922A: Swift detection of a burst
- GRB 260917C: AstroSat CZTI detection
- GRB 260921A: AstroSat CZTI detection
- GRB 260921A: Swift-BAT refined analysis
- GRB 260921B: Fermi GBM Final Localization
- GRB 260921A: Fermi GBM Observation
- EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
- EP Alert 260921.58: Global MASTER-Net observations report
- GRB 260917B:: SVOM/ECLAIRs refined analysis
- The EP-WXT trigger 01709319528 is likely a flaring star
- EP260920a: VLT/HAWK-I near-infrared candidate
- Swift GRB 260921A: Global MASTER-Net observations report
- GRB 260921A: Swift detection of a burst
- EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
- GRB 260921A: Fermi GBM Final Real-time Localization
- EP260920b: LCO observations
- GRB 260920A: AstroSat CZTI detection
- EP260920b: SVOM/VT optical observation
- EP260920b: COLIBRÍ optical observations
- EP260920b: LCO optical counterpart detection
- The EP-WXT trigger 01709318601 is likely a flaring star
- EP Alert 260921.01: Global MASTER-Net observations report
- EP260920b: Global MASTER-Net observations report
- EP Alert 260920.66: Global MASTER-Net observations report
- EP260920a: NOT early time optical upper limits
- EP260920a: NOT optical upper limits
- GRB 260920A: Fermi GBM Final Real-time Localization
- EP260920a: SVOM/VT optical upper limits
- EP260917a: Global MASTER-Net observations report
- EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
- EP260920a: COLIBRÍ optical upper limits
- IceCube Alert 260919A: Global MASTER-Net observations report
- EP260920a: LCO optical counterpart candidate
- EP Alert 260919.40: Global MASTER-Net observations report
- IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
- The EP-WXT trigger 01709318491 is likely a flaring star
- EP260917a: SVOM/VT optical upper limits
- GRB 260918A: SVOM/C-GFT optical upper limits
- EP Alert 260918.62: Global MASTER-Net observations report
- Fermi GBM Sub-Threshold Detection of GRB 260918A
- EP Alert 260918.24: Global MASTER-Net observations report
- SVOM GRB260918.16: Global MASTER-Net observations report
- Konus-Wind detection of GRB 260916B (short/hard)
- The EP-WXT trigger 01709318279 is likely a flaring star