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"11546 results found.
- LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
- LIGO/Virgo S190519bj: Fermi-LAT search for a high-energy gamma-ray counterpart
- Fermi GRB190520.6 Global MASTER-Net observations report
- GRB 190519A: AstroSat CZTI detection
- GRB 190519A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo S190519bj: Fermi GBM Observations
- GRB 190519A: Fermi GBM observation
- GRB 190519A: Fermi GBM Final Real-time Localization
- Fermi GRB190517.81 Global MASTER-Net observations report
- Fermi Trigger 579814215 / GRB 190517813 / GRB190517A: BALROG localization
- GRB 190517A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190517h: Fermi GBM Observations
- GRB 190515A: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB190517.1 Global MASTER-Net observations report
- Fermi GRB190515.49 Global MASTER-Net observations report
- GRB 190515A: Insight-HXMT/HE detection
- GRB 190515A: Fermi GBM detection
- GRB 190515A: Fermi-LAT detection
- Fermi GRB190515.43 Global MASTER-Net observations report
- GRB 190510A: CALET Gamma-Ray Burst Monitor detection
- GRB 190515A: Fermi GBM Final Real-time Localization
- Fermi GRB190514.67 Global MASTER-Net observations report
- LIGO/Virgo S190513bm: Fermi GBM Observations
- Konus-Wind observation of GRB 190511A
- LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190512at: Fermi GBM Observations
- GRB 190512A: Fermi GBM observation
- Fermi GRB190512.62 Global MASTER-Net observations report
- Fermi GRB190512.61 Global MASTER-Net observations report
- GRB 190512A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 190510A (short)
- GRB 190511A: NOT optical afterglow
- GRB 190511A: Fermi-LAT detection
- GRB 190511A: Fermi GBM observation
- LIGO/Virgo S190510g: DESGW counterpart candidates over 80% of the GW localization area
- GRB 190511A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190510g: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 190510A: Fermi GBM Final Real-time Localization
- Fermi GRB190510.12 Global MASTER-Net observations report
- LIGO/Virgo S190510g: Fermi GBM Observations
- GRB 190508A: GOTO optical search - no counterparts
- GRB 190508B: Fermi GBM Final Real-time Localization
- Fermi GRB190508.81 Global MASTER-Net observations report
- GRB 190508A: Fermi GBM Final Real-time Localization
- Fermi GRB190507.71 Global MASTER-Net observations report
- GRB 190507B: GOTO optical counterpart search
- Fermi GRB190508.11 Global MASTER-Net observations report
- Fermi GRB190507.97 Global MASTER-Net observations report
- GRB 190507B: Fermi GBM Final Real-time Localization
- Fermi GRB190507.27 Global MASTER-Net observations report
- IceCube-190504A: MASTER optical monitoring analysis
- Fermi Trigger 578903308 / GRB 190507270 / GRB190507A: BALROG localization
- GRB 190507A: Fermi GBM Final Real-time Localization
- Fermi GRB190506.58 Global MASTER-Net observations report
- Update to the Fermi GBM GCN Reporting
- IceCube-190504A: Swift-XRT Follow-up Observations
- Fermi GRB190505.82 Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-190504A
- Fermi GRB190505.05 Global MASTER-Net observations report
- Fermi GRB190504.68 Global MASTER-Net observations report
- IPN triangulation of GRB 190504A (short)
- LIGO/Virgo S190503bf: Fermi-LAT search for a high-energy gamma-ray counterpart
- Fermi-LAT Gamma-ray Observations of IceCube-190503A
- LIGO/Virgo S190503bf: Fermi-GBM Observations
- Fermi-GBM Observations of IceCube-190503A
- IceCube-190503A - IceCube observation of a high-energy neutrino candidate event
- IPN Triangulation of GRB 190501A (long/bright)
- Fermi Trigger 578462495 / GRB 190502168 / GRB190502A: BALROG localization
- Fermi GRB190501.79 Global MASTER-Net observations report
- Fermi GRB190429.74 Global MASTER-Net observations report
- LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
- GRB 190427A: CALET Gamma-Ray Burst Monitor detection
- Fermi Trigger 578170097 / GRB 190428783 / GRB190428A: BALROG localization
- GRB 190419A: AstroSat CZTI detection
- Fermi GRB190427.19 Global MASTER-Net observations report
- GRB 190427A: Fermi GBM detection
- LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190426c: Fermi GBM Observations
- LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190425z: Fermi GBM Observations
- LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation
- LIGO/Virgo S190421ar: Fermi-LAT search for a high-energy gamma-ray counterpart
- Fermi GRB190425.09 Global MASTER-Net observations report
- GRB 190422A: Fermi GBM detection
- Fermi GRB190422.96 Global MASTER-Net observations report
- Fermi GRB190422.67 Global MASTER-Net observations report
- LIGO/Virgo S190421ar: Fermi-GBM Observations
- Fermi GRB190420.98 Global MASTER-Net observations report
- Fermi GRB190419.41 Global MASTER-Net observations report
- Fermi trigger 576241792 / GRB 190406B: MASTER optical observation
- Fermi Trigger 577360542 / GRB 190419414 / GRB190419A: BALROG localization
- Fermi GRB190418.92 Global MASTER-Net observations report
- GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
- IPN Triangulation of GRB 190415A
- Fermi GRB190417.46 Global MASTER-Net observations report
- GRB 190415A: Insight-HXMT/HE detection
- Fermi Trigger 576994194 / GRB 190415173 / : BALROG localization
- Fermi GRB190415.17 Global MASTER-Net observations report