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"12274 results found.
- Fermi GRB 260926A: Global MASTER-Net observations report
- GRB 260924A: Near-infrared detection with MDM/MIRAGE
- GRB 260926A: Fermi GBM Final Real-time Localization
- 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 260924A: SVOM/GRM observation
- GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
- GRB 260923A: Insight-HXMT/HE detection
- GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
- GRB 260924A: GROWTH-India Telescope optical observations
- GRB 260924A: NuSTAR detection of prompt emission
- GRB 260921A: NuSTAR detection of prompt emission
- GRB 260921A: SVOM/GRM observation
- 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: detection of a bright optical afterglow by the 1.5m OSN telescope
- GRB 260924A: Fermi GBM Final Real-time Localization
- Fermi GRB 260923A: Global MASTER-Net observations report
- GRB 260923A: Fermi GBM Final Real-time Localization
- Fermi-LAT Gamma-ray Observations of IceCube-260919A
- Fermi-LAT Gamma-ray Observations of IceCube-260916A
- Fermi-LAT Gamma-ray Observations of IceCube-260805A
- GRB 260920A: Glowbug gamma-ray detection
- GRB 260918A: SVOM/ECLAIRs refined analysis
- GRB 260917C: AstroSat CZTI detection
- GRB 260921A: AstroSat CZTI detection
- GRB 260921B: Fermi GBM Final Localization
- GRB 260921A: Fermi GBM Observation
- GRB 260921A: Fermi GBM Final Real-time Localization
- GRB 260920A: AstroSat CZTI detection
- IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260920A: Fermi GBM Final Real-time Localization
- IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
- Fermi GBM Sub-Threshold Detection of GRB 260918A
- Konus-Wind detection of GRB 260916B (short/hard)
- GRB 260916B: Glowbug gamma-ray detection of a short burst
- IPN triangulation of GRB 260916B (short)
- GRB 260917C: Fermi GBM Final Real-time Localization
- GRB 260916B: Fermi GBM Detection
- IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260916B: Fermi GBM Final Localization
- GRB 260917A: Glowbug gamma-ray detection
- GRB 260915A: SVOM/ECLAIRs refined analysis
- GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
- GRB 260917A: Fermi GBM Final Real-time Localization
- Fermi trigger No 811304653: Global MASTER-Net observations report
- Fermi trigger No 811264269: Global MASTER-Net observations report
- IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 260914A: SVOM/GRM observation
- GRB 260914A: Mondy and TShAO optical observations
- GRB 260914A: SVOM/ECLAIRs refined analysis
- GRB 260914A: REM optical/NIR observations
- Fermi GBM Sub-Threshold Detection of GRB 260915A
- Fermi GBM Sub-Threshold Detection of GRB 260914A
- GRB 260907A: SVOM/GRM observation
- GRB 260910B: GOTO tentative optical counterpart candidates
- GRB 260910B: Fermi GBM Final Real-time Localization
- GRB 260910A: Fermi GBM Final Real-time Localization
- Fermi trigger No 810554827: Global MASTER-Net observations report
- GRB 260907A: Glowbug gamma-ray detection of a likely short burst
- Fermi GRB 260907B: Global MASTER-Net observations report
- GRB 260907B: Fermi GBM Final Real-time Localization
- Fermi GRB 260907A: Global MASTER-Net observations report
- GRB 260907A: Fermi GBM Final Real-time Localization
- GRB 260831A: GECAM-B observation
- GRB 260827A: Insight-HXMT/HE detection
- Konus-Wind detection of GRB 260829A
- GRB 260829A: SVOM/GRM observation
- IceCube-260827A: No transient candidates from the Zwicky Transient Facility
- GRB 260829A: AstroSat CZTI detection
- GRB 260827A: SVOM/GRM observation
- IPN triangulation of GRB 260829A
- GRB 260827A: Glowbug gamma-ray detection
- GRB 260831A: Fermi GBM Final Real-time Localization
- Fermi-LAT Gamma-ray Observations of IceCube-260827A
- Fermi-LAT Gamma-ray Observations of IceCube-260825A
- GRB 260829A: GECAM-B observation of a long burst
- GRB 260825A: SVOM/GRM observation of a long burst
- GRB 260825A: GECAM-B observation
- GRB 260829A: Fermi GBM Detection
- GRB 260825A: AstroSat CZTI detection
- GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
- GRB 260829A: Fermi GBM Final Real-time Localization
- IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
- Fermi GBM trigger 809666623/260829141 is not a GRB
- IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 260827A: Fermi GBM Final Real-time Localization
- IceCube-260825A: No transient candidates from the Zwicky Transient Facility
- GRB 260809A: SVOM/ECLAIRs refined analysis
- IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260825A: Fermi GBM Final Real-time Localization
- IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB260822B: Fermi GBM Final Localization