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"32580 results found.
- GRB 251222A/EP251222b: Optical detection with Kinder observations
- EP251222a: Optical upper limit with Kinder observations
- GRB 251221A: Swift-BAT refined analysis
- GRB 251222A/EP251222b: FTW optical and NIR observations
- EP251222a: FTW optical and NIR observations
- GRB 251205A: Kilonova-Catcher optical afterglow detection
- GRB 251222A: AbAO optical observations
- GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
- GRB 251129A / EP251129a: VLA detection of a radio counterpart
- EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
- GRB 251222A: ZTSH BVRI optical observations
- GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
- GRB 251222A: Continued 1.3m DFOT optical observation
- EP251220a: 3.6m DOT optical afterglow detection
- GRB 251222A: Fermi GBM Observation
- EP251220a: CrAO ZTSh optical observations
- EP251221a: PRIME upper limit
- EP251222a: Global MASTER-Net observations report
- GRB 251222A / EP251222b: GECAM-B observation
- EP251221a: Liverpool Telescope upper limits
- EP251222a: refined analysis of the EP-WXT and EP-FXT observations
- EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
- Konus-Wind detection of GRB 251222A / EP251222b
- GRB 251222A / EP251222b: LCO detection of the optical counterpart
- EP251222a: NTT/ULTRACAM optical observations
- EP251222a: GOTO optical upper limit
- GRB 251222A / EP251222b: GOTO optical counterpart detection
- GRB 251222A / EP251222b: LCO optical observations
- GRB 251222A: 1.3m DFOT optical detection
- GRB251221A: 7DT optical upper limits
- EP251222a: GSP Optical Counterpart Detection
- GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
- GRB 251222A / EP251222b: SVOM/VT optical rebrightening
- EP251222b/GRB 251222A: SVOM/GRM observation
- EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
- EP251221a: Global MASTER-Net observations report
- GRB 251222A: PRIME near-infrared detection
- EP251221a: NOT optical upper limit
- GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
- GRB 251222A: NOT optical observations
- IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
- IPN triangulation of GRB 251220B (short)
- GRB 251222A: Swift ToO observations
- GRB 251222A: SVOM/VT optical candidate
- GRB 251222A: SVOM detection of a long burst
- EP251220a: PRIME upper limit
- EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
- GRB 251221A: PRIME near-infrared observation
- EP251220a: NOT optical observations
- EP251220a: FTW optical and NIR observations
- GRB 251221A: UAFO and Mondy optical upper limit
- GRB 251221A: Swift/UVOT Upper Limits
- GRB 251221A: Fermi GBM Observation
- EP251220a: EP-FXT follow-up observation
- GRB 251220B: SVOM/GRM observation of a short burst
- EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
- EP 251220a: GOTO optical counterpart detection
- GRB 251221A: COLIBRÍ detection of the optical counterpart
- EP 251220a: COLIBRÍ detection of the optical counterpart
- EP251220a: Global MASTER-Net observations report
- GRB 251219A: SVOM/GRM observation of a short burst
- Fermi-LAT Gamma-ray Observations of IceCube-251218A
- IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-251218A: COLIBRÍ optical upper limits
- GRB 251214B: VIRT Optical Upper Limit
- Fermi GRB 251217A: Global MASTER-Net observations report
- GRB 251215A: Swift/UVOT Upper LImits
- GRB 251215A: Fermi GBM Observation
- Fermi GRB 251216A: Global MASTER-Net observations report
- GRB 251202A/EP251202a: Koshka optical upper limit
- GRB 251214B: Mondy optical upper limit
- GRB 251215A: COLIBRÍ optical upper limit
- EP251214b: KAIT optical upper limit
- Fermi GRB 251215A: Global MASTER-Net observations report
- EP251214a: Optical upper limit with Kinder observations
- GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
- GRB 251215A: Glowbug gamma-ray detection
- GRB 251214B: UAFO optical upper limit
- GRB 251214B: VLT/X-shooter observations
- GRB 251213A: GRID-10B observation
- GRB 251214B: Swift-BAT refined analysis
- GRB 251202A: radio detection with the VLA
- EP251214b: Global MASTER-Net observations report
- EP251214b : Einstein Probe detection of a fast X-ray transient
- EP251214b : Einstein Probe detection of a fast X-ray transient
- GRB 251214B: AbAO optical observations
- GRB 251214B: LCO detection of the optical counterpart
- GRB 251209A: GECAM-B observation of a long burst
- GRB 251214D: GECAM-B observation of a long burst
- GRB 251214B: Fermi GBM Observation
- GRB 251209A: Insight-HXMT/HE detection
- GRB 251215A: Swift ToO observations
- EP251214b (EP trigger 01709250023): LCO optical limits
- GRID detection of GRB 251213A
- GRB 251203B: AbAO optical observations
- GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 251214B: GECAM-B observation of a long burst
- GRB 251213A: SVOM/GRM observation
- EP251214a: KAIT optical upper limit
- GRB 251213A: AstroSat CZTI detection