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"
24598 results found.
- GRB 231117A: ATLAS non-detection of an optical counterpart
- GRB 231115A : OHP/T120 optical upper limit
- GRB 231117A : MITSuME Akeno optical upper limits
- GRB 231117A: Enhanced Swift-XRT position
- GRB 231117A: AstroSat CZTI detection of a bright short burst
- GRB 231117A: Swift detection of a bright short burst
- GRB 231115A: Non-detection of radio emission with CHIME/FRB
- GRB 231111A: Swift/UVOT Detection
- MAGIC observation of GRB 231115A, a possible magnetar giant flare
- GRB231115A: Liverpool Telescope imaging
- GRB 231115A: NuSTAR Follow-Up Observations
- GRB 231115A: Swift/BAT-GUANO detection of a short burst
- GRB 231115A: Swift-XRT and Swift-UVOT observations
- GRB 231115A: AGILE/MCAL upper limits
- GRB 231115A: Insight-HXMT/HE detection
- GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
- GRB 231115A : MITSuME Akeno and Okayama optical upper limits
- GRB 231115A: Gaoyazi/GOT follow-up and archival observations
- GRB 231115A / AT2023xvj: Updated GIT analysis
- GRB 231115A: Upper limits from a neutrino search with IceCube
- GRB 231115A: Kinder observations with Lulin observatory
- GRB231115A: GRANDMA Observations
- GRB 231115A: GOTO pre-burst limits of AT2023xvj
- GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
- GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
- GRB 231106A: TESS identification of candidate optical counterpart
- GRB 231115A (short): Glowbug gamma-ray detection
- GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
- GRB 231115A: archival HST observations
- GRB 231115A: GROWTH-India discovery of a potential optical counterpart
- GRB 231115A: significance of INTEGRAL localization alignment with M82
- LIGO/Virgo/KAGRA S231113bw: Updated Sky localization, EM Bright Classification, and Source Classification
- GRB 231111A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S231114n: Updated Sky localization
- GRB 231113A (short): Glowbug gamma-ray detection
- GRB 231114A (short): Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
- GECAM-B observation of a short burst from SGR J1555-5402
- LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
- LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
- SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
- 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
- GRB 231110A: Swift-BAT refined analysis
- GRB 231106A: Glowbug gamma-ray detection
- GRB 231111A: Xinglong-2.16m optical observations
- LIGO/Virgo/KAGRA S231113bb: Identification of a GW compact binary merger candidate
- GRB 231104A: VZLUSAT-2 detection
- GRB 231110A: Glowbug gamma-ray detection
- GRB 231111A: Leavitt Observatory optical observations
- GRB231111A: Optical follow-up observations with Mephisto
- GRB 231111A: GMG observation (correction)
- GRB 231111A: GMG observation upper limit
- GRB 231106B: GRBAlpha detection
- GRB 231110A: Terskol Zeiss-2000 optical upper limit
- GRB 231111A: Swift-XRT refined Analysis
- GRB 231111A: Mondy optical observations
- GRB 231111A: Enhanced Swift-XRT position
- GRB 231110A: SAO RAS optical observations
- GRB231111A: GIT confirmation of the optical afterglow
- GRB 231111A: Nanshan/HMT optical observations
- GRB 231111A: Swift detection of a burst with an optical counterpart
- Swift GRB231111.60: Global MASTER-Net observations report
- GRB231110A: WFST Observation and upper limits
- GRB 231110A: Swift detection of a burst
- 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
- GRB 231104A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
- GRB 231104A: NuSTAR Observation of the prompt emission
- GRB 231104A: 3.6m DOT optical upper limit
- 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
- Fermi-LAT gamma-ray observations of IceCube-231103A
- GRB 231104A: NOT upper limit
- GRB 231104A: Fermi GBM Observation
- Fermi GRB 231103A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
- GRB 231104A: AKO Upper Limit
- GRB 231104A: AstroSat CZTI detection
- GRB 231104A: Swift-XRT refined Analysis
- GRB 231104A: Fermi-LAT detection
- LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
- GRB 231104A: Swift/UVOT Upper Limits
- GRB 231104A: Enhanced Swift-XRT position
- GRB231104A: LCOGT Optical Upper Limits
- GRB 231104A: Swift detection of a bright burst
- Fermi-LAT gamma-ray observations of IceCube-231027A
- LIGO/Virgo/KAGRA S231102w: Updated Sky localization
- GRB 231101A: Glowbug gamma-ray detection
- LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
- New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
- GRB 231101A: Fermi GBM Final Real-time Localization
- GRB 231028B: VZLUSAT-2 detection