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"7447 results found.
- GRB 190114C: Optical follow-up from HCT
- Swift Trigger 885960: A third Swift trigger on MAXI J1348-630
- Search for counterpart to IceCube-190124A with ANTARES
- IceCube-190124A - IceCube observation of a high-energy neutrino candidate event
- GRB 190123A: Swift detection of a burst
- Trigger 884906: Swift detection of MAXI J1631-479
- GRB 190114C: Optical detection from HCT
- GRB 190114C: A type 1 BdHN with TeV emission
- INTEGRAL observation of IceCube-190104A
- GRB 190114C: Swift detection of a very bright burst with a bright optical counterpart
- GRB 190114B: Swift detection of a burst
- GRB 190114A: Possible UVOT Detection
- GRB 190114A: Swift detection of a burst
- GRB 190109B: Swift detection of a burst
- GRB 190109A: Swift detection of a burst
- IceCube-190104A: Swift-XRT observations
- GRB 190106A: Swift detection of a burst with an optical counterpart
- Search for counterpart to IceCube-190104A with ANTARES
- IceCube-190104A - IceCube observation of a high-energy neutrino candidate event
- GRB 190103B: Swift detection of a burst
- GRB 181225A: KAIT Follow-Up Observations with Upper Limit
- GRB 181228A: KAIT Optical Upper Limit
- GRB 181228A: Swift detection of a burst
- GRB 181222B: Swift ToO observations
- GRB 181225A: Swift observations and X-ray candidate afterglow
- GRB 181225A: Swift ToO observations
- Trigger 878548: Swift detection of AX 1631.9-4752
- Swift Trigger 878504 is not astrophysical
- GRB181213A: Swift/UVOT Detection
- Swift Trigger 874754 is likely not an astrophysical event
- Fermi-GBM Observations During Four New GW-Detected BBH Mergers (Correction)
- Fermi-GBM Observations During Four New GW-Detected BBH Mergers
- GRB 181203A: Swift detection of a burst
- GRB 181202A: Swift detection of a burst with an optical counterpart
- GRB 181201A: Swift ToO observations
- GRB 181126A: Swift detection of a burst
- GRB 181123B: Swift detection of a short burst
- Swift Trigger 872470 is probably not a GRB
- GRB 181110A: Swift detection of a burst with an optical counterpart
- Swift Trigger 871103 is not an astrophysical event
- Fermi GRB 181105.31: Global MASTER Net optical observations
- GRB 181103A: Swift detection of a burst
- Fermi-LAT Gamma-ray Observations of IceCube-181023A
- IceCube-181023A - IceCube observation of a high-energy neutrino candidate event
- GRB 181023A: KAIT Optical Upper Limit
- GRB 181023A: Swift detection of a burst
- GRB 181022A: Swift detection of a burst
- GRB 181020A: Swift detection of a burst with an optical counterpart
- IceCube-181014A - IceCube observation of a high-energy neutrino candidate event
- GRB 181013A: Swift detection of a probable burst
- GRB 181010A: MASTER-Argentina OT detection
- GRB 181010A: Swift detection of a burst with an optical counterpart
- GRB 181002A: Swift detection of a burst
- GRB 180930A: KAIT Optical Upper Limit
- GRB 180930A: Swift detection of a burst
- GRB 180925A: Swift detection of a burst
- GRB 180924A: Swift detection of a burst
- Swift Trigger 863053 is not an astrophysical event
- GRB 180923A: MASTER inspection MAXI/GSC error box
- GRB 180914B: KAIT Optical Afterglow Candidate
- GRB 180914B: Tiled Swift observations
- GRB 180914A: MASTER automatic inspection
- GRB 180914A: Tiled Swift observations
- Fermi-LAT Gamma-ray Observations of IceCube-180908A
- INTEGRAL observation of IceCube-180908A
- Search for counterpart to IceCube-180908A with ANTARES
- GRB 180715A: 15 GHz upper limits from the AMI Short GRB Program
- GRB 180718A: 15 GHz upper limits from the AMI Short GRB Program
- IceCube-180908A - IceCube observation of a high-energy neutrino candidate event
- GRB 180905A: Swift detection of a burst
- GRB 180904A: NOT optical observations, candidate host galaxy
- GRB 180904A: Swift detection of a burst
- GRB 180829A: Tiled Swift observations
- GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
- GRB 180818B: TSHAO optical upper limit
- GRB 180823A: Swift detection of a burst
- GRB 180821A: iTelescope counterpart is not the afterglow
- GRB 180818B: 1.5m OSN optical afterglow candidate
- GRB 180821A: Swift detection of a burst
- GRB 180818B: Swift detection of a burst
- GRB 180818A: Swift detection of a burst
- GRB 180809A: further Swift/XRT observations
- Correction: Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
- LIGO/Virgo GW170817: A steep decline in the radio light curve and prediction for the X-rays
- Chandra X-ray observations of GW170817 at 1 year post-merger: increasingly rapid fading
- GRB 180812A: Swift detection of a burst
- Swift Trigger 852625: a possible GRB
- GRB 180809B: Swift detection of a burst with an optical afterglow
- GRB 180809A: Tiled Swift observations
- GRB 180806A: NOT optical observations
- GRB 180806A: Swift ToO observations
- GRB 180805B: Swift detection of a burst
- GRB 180805A: Swift detection of a burst
- GRB 180728A: A long GRB of the X-ray flash (XRF) subclass, expecting supernova appearance
- GRB 180728B: MASTER optical observations short GRB IPN error box
- GRB 180727A: Swift detection of a burst
- GRB 180721A: KAIT Optical Upper Limit
- GRB 180720B: Testing the universality of the newly born neutron star in BdHNe
- GRB 180722A: Tiled Swift observations
- ANTARES neutrino Alert180713.02: MASTER optical observation