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"4055 results found.
- GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
- GRB 231106A: TESS identification of candidate optical counterpart
- LIGO/Virgo/KAGRA S231113bw: Updated Sky localization, EM Bright Classification, and Source Classification
- LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
- LIGO/Virgo/KAGRA S231114n: Updated Sky localization
- LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
- LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
- LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231113bb: Updated Sky localization
- LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231113bb: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231112ag: Retraction of GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231110g: Updated Sky localization
- LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231108u: Updated Sky localization
- LIGO/Virgo/KAGRA O4 Landscape
- LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
- IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
- LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
- LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231102w: Updated Sky localization
- LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
- New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
- IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231030av: Retraction of GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
- LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
- LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
- LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
- LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231018cb: One counterpart neutrino candidate event from an IceCube neutrino search
- GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
- IceCube-231014A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
- LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231008ap: Updated Sky localization
- LIGO/Virgo/KAGRA S231008ap: Identification of a GW compact binary merger candidate
- IceCube-231004A: Upper limits from a search for additional neutrino events in IceCube
- LIGO/Virgo/KAGRA S231005ah: Updated Sky localization
- LIGO/Virgo/KAGRA S231005ah: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231005j: Updated Sky localization
- LIGO/Virgo/KAGRA S231005j: Identification of a GW compact binary merger candidate
- Update of IceCube-231004A - Corrected direciton
- LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
- LIGO/Virgo/KAGRA S230930al: Updated Sky localization
- LIGO/Virgo/KAGRA S230928cb: Updated Sky localization
- LIGO/Virgo/KAGRA S231001aq: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230930al: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230927be: Updated Sky localization
- LIGO/Virgo/KAGRA S230927l: Updated Sky localization
- LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
- Swift Triggers 1192740, 1192742 and 1192743 are not astrophysical events
- LIGO/Virgo/KAGRA S230922q: Updated Sky localization
- LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
- LIGO/Virgo/KAGRA S230924an: Updated Sky localization
- LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
- LIGO/Virgo/KAGRA S230922g: Updated Sky localization
- LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230922q: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
- LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
- LIGO/Virgo/KAGRA S230920al: Updated Sky localization
- LIGO/Virgo/KAGRA S230919bj: Updated Sky localization
- LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
- LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
- LIGO/Virgo/KAGRA S230918aq: Retraction of GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
- LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
- LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO