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"
4714 results found.
- Fermi trigger No 722507896: Global MASTER-Net observations report
- Fermi trigger No 722462310: Global MASTER-Net observations report
- Fermi trigger No 722400249: Global MASTER-Net observations report
- GRB 231117A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
- GRB 231117A: MAAO 0.7-m telescope optical upper limit
- GRB 231117A: GECAM-C detection
- GRB 231117A: GRBAlpha detection
- GRB 231117A: REM optical and NIR early-time observations
- GRB 231117A (short): Glowbug gamma-ray detection
- GRB 231117A: ATLAS non-detection of an optical counterpart
- Konus-Wind detection of GRB 231117A (short/hard)
- GRB 231115A: optical observations from INAF observatories
- GRB 231117A: AGILE detection of a bright short burst
- GRB 231117A: AstroSat CZTI detection of a bright short burst
- GRB 231117A: Swift detection of a bright short burst
- GRB231115A: Liverpool Telescope imaging
- GRB 231115A: archival HST observations
- Fermi GRB 231115A: Global MASTER-Net observations report
- GRB 231111A: GMG observation (correction)
- GRB 231111A: GMG observation upper limit
- LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
- IceCube-231103A: No candidates from the Zwicky Transient Facility
- Fermi trigger No 721204446: Global MASTER-Net observations report
- Fermi GRB 231108A: Global MASTER-Net observations report
- GRB 231108A: Fermi GBM Final Real-time Localization
- Fermi GRB 231106A: Global MASTER-Net observations report
- IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
- Fermi-LAT gamma-ray observations of IceCube-231103A
- Fermi GRB 231103A: Global MASTER-Net observations report
- GRB231104A: LCOGT Optical Upper Limits
- IceCube Alert 231103.39: Global MASTER-Net observations report
- IceCube-231103A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
- Fermi trigger No 720498201: Global MASTER-Net observations report
- Fermi GRB 231030B: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
- Fermi trigger No 720224759: Global MASTER-Net observations report
- IceCube Alert 231027.18: Global MASTER-Net observations report
- 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
- IceCube-231004A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-231004A: No significant detection in HAWC
- GRB 231003A is not a GRB
- LIGO/Virgo/KAGRA S230922g: DECam GW-MMADS candidates
- LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
- Fermi GBM Statement for Trigger 716527670/230916144
- AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
- ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
- GRB 230911A: Fermi GBM Observation
- Swift GRB230916.13: Global MASTER-Net observations report
- GRB 230911A: Swift-XRT afterglow detection
- Fermi trigger No 716449174: Global MASTER-Net observations report
- GRB 230911A: GOTO optical counterpart candidate
- IPN triangulation of GRB 230911D (long)
- GRB 230911A: Fermi GBM Final Real-time Localization
- GRB 230910A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S230908b: one counterpart neutrino candidate from IceCube neutrino searches
- GRB 230205A: LBT spectroscopy of two host galaxy candidates
- Fermi GRB 230906A: Global MASTER-Net observations report
- Fermi trigger No 715429986: Global MASTER-Net observations report
- Swift GRB230903.72: Global MASTER-Net observations report
- Fermi GRB 230827A: Global MASTER-Net observations report
- Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
- Fermi trigger No 714618399: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230822bm: Identification of a GW compact binary merger candidate
- GRB 230815A: ATCA detection of radio counterpart
- GRB 230818A: Tautenburg observations
- GRB 230818A: Bassano Bresciano Observatory optical observations
- GRB 230818A: KGO RC-25 optical observations
- GRB 230818A: Swift/UVOT Detection
- GRB 230818A: SAO RAS Zeiss-1000 observations
- Fermi GRB 230818A: Global MASTER-Net observations report
- GRB 230817A: AstroSat CZTI detection
- GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
- GRB 230815A: SOAR/Goodman follow-up imaging
- GRB 230815A: Swift-BAT refined analysis
- GRB 230815A: Enhanced Swift-XRT position
- GRB 230815A: Swift detection of a burst
- GRB 230812B: further SAO RAS optical observations
- GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
- LAT GRB230812.79: Global MASTER-Net observations report
- Fermi GRB 230812B: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
- Fermi trigger No 713136868: Global MASTER-Net observations report
- Fermi trigger No 713205976: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230808i: Identification of a GW unmodeled transient candidate
- Fermi trigger No 712927418: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
- Fermi trigger No 712798043: Global MASTER-Net observations report
- GRB 230803A: AstroSat CZTI detection
- Fermi trigger No 712718833: Global MASTER-Net observations report
- Fermi trigger No 712713532: Global MASTER-Net observations report
- Fermi trigger No 712651827: Global MASTER-Net observations report
- Swift GRB 230802A: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
- GRB 230728A: LCOGT Optical Upper Limit
- GRB 230727A: AstroSat CZTI detection