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"7445 results found.
- LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/VIRGO G275697: Fermi GBM Observations
- LIGO/Virgo G275697 ANTARES search
- LIGO/Virgo G275697: IceCube neutrino observations
- LIGO/Virgo G275697: Identification of a GW CBC Candidate
- LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
- LIGO/Virgo G275404: REM optical/NIR observations
- LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
- LIGO/Virgo G275404 ANTARES search
- LIGO/Virgo G275404: AGILE-GRID preliminary analysis
- LIGO/Virgo G275404: Fermi GBM Observations
- LIGO/Virgo G275404: AGILE MCAL observations
- LIGO/Virgo G275404: IceCube neutrino observations
- LIGO/Virgo G275404: Identification of a GW CBC Candidate
- GRB 170222A: Swift-XRT observations
- LIGO/Virgo G274296: HAWC follow-up
- GRB 170222A: Tiled Swift observations
- GRB 170222A: Swift ToO observations
- LIGO/Virgo G274296: No change to estimate of LIGO false alarm probability
- Swift Trigger 739517 is probably not a GRB
- LIGO/Virgo G274296: iPTF Optical Transient Candidates
- LIGO/Virgo G274296: Global MASTER Net PSN and QSO detection
- LIGO/Virgo G274296: Asiago 1.82m Optical Observations
- LIGO/Virgo G274296: IceCube neutrino observations
- LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G274296: AstroSat CZTI upper limits
- LIGO/Virgo G274296 ANTARES search
- LIGO/Virgo G274296: CNEOST imaging coverage and an optical transient
- LIGO/Virgo G274296: Global MASTER Net two OTs detection
- LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G274296: REM optical/NIR observations
- LIGO/VIRGO G274296: Fermi GBM Observations
- LIGO/Virgo G274296: Identification of a GW Burst Candidate
- Trigger 738728: Swift triggered on noise near NGC 4096
- GRB 170214A: NOT optical afterglow confirmation
- GRB 170214A: Swift ToO observations
- GRB 170209A: Swift ToO observations
- GRB 170208B WHT nIR candidate afterglow
- GRB 170208B: GROND observations
- GRB 170208B: Swift detection of a burst
- GRB 170208A: Swift detection of a burst
- LIGO/Virgo G270580: ANTARES upper limits
- GRB 170206B: Swift detection of a burst
- GRB 170205A: Swift detection of a burst with an optical counterpart
- GRB 170202A: Swift detection of a burst with an optical afterglow
- GRB 170131A: Swift ToO observations
- LIGO/Virgo G268556: FLOYDS Spectrum of iPTF17cf/PS17fr Favors an AGN Classification
- GRB 170127C: Tiled Swift observations
- GRB 170127B: Swift detection of a short burst
- GRB 170127A: Swift detection of a burst
- GRB 170126A: Swift detection of a burst with an optical counterpart
- GRB 170115B: AGILE/SuperAGILE localisation
- LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G268556: ANTARES upper limits
- GRB 170121B: AbAO optical observations
- GRB 170121B: Swift-XRT and UVOT observations
- GRB 170121B: Swift ToO observations
- LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
- LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
- LIGO/Virgo G270580 ANTARES search
- LIGO/Virgo G270580: Identification of a GW Burst Candidate
- GRB 170117A: Swift ToO observations
- GRB 170115B: Tiled Swift observations
- GRB 170115A: Swift detection of a burst
- GRB 170113A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
- GRB 170112A: REM optical/NIR observations
- GRB 170112A: Swift detection of a short burst
- LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
- LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
- GRB 170111A: Swift detection of a burst
- LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
- LIGO/Virgo G268556: iPTF Optical Transient Candidates
- Swift Trigger 730874 is not astrophysical
- LIGO/Virgo G268556: Updated sky map from gravitational-wave data
- Swift Trigger 730513 is not an astrophysical event
- LIGO/Virgo G268556: ANTARES search
- LIGO/Virgo G268556: Fermi GBM Observations
- LIGO/Virgo G268556: Identification of a GW CBC Candidate
- GRB 161220A: Swift detection of a burst
- GRB 161219B: Swift detection of a burst with an optical afterglow
- Swift Trigger 727422 is not an astrophysical event.
- GRB 161217A: Swift detection of a burst
- IceCube-161210: Konus-Wind upper limits
- IceCube-161210: CALET Gamma-Ray Burst Monitor upper limits
- GRB 161214A: fading optical afterglow candidate with the LT
- INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161210
- IceCube-161210: IceCube observation of a high-energy neutrino candidate event
- GRB 161129A: NOT optical observations and candidate host galaxy
- GRB 161202A: Swift detection of a burst
- GRB 160821B: HST detection of the optical and IR counterpart
- GRB 161129A: Swift detection of a burst
- GRB 161123A: Tiled Swift observations
- Swift Trigger 723124 is probably not a GRB
- Swift Trigger 722681 is probably not a GRB
- GRB 161117B: Swift detection of a burst